TWI789712B

TWI789712B - Headphone driver and driving method thereof

Info

Publication number: TWI789712B
Application number: TW110106250A
Authority: TW
Inventors: 林曉銘
Original assignee: 旺宏電子股份有限公司
Priority date: 2021-02-23
Filing date: 2021-02-23
Publication date: 2023-01-11
Also published as: TW202234900A

Abstract

A headphone driver is used to drive a headphone apparatus, which includes a first differential driver, a first positive output terminal, a first negative output terminal, and a second negative output terminal. The first positive output terminal is connected to the first terminal. A switch unit is disposed on a feedback path at the first and second negative output terminal and the second negative output terminal, to enable the first negative output terminal in feedback as a close loop to output to the third terminal and disable the second negative output terminal in feedback and disable output of the second negative output terminal as an open loop at a first operation state, and enable the second negative output terminal in feedback as a close loop to output to the fourth terminal and disable the first negative output terminal in feedback and disable output of the first negative output terminal as an open loop at a second operation state. The first differential driver includes a first positive voltage driving circuit, a first negative voltage driving circuit and a second negative voltage driving circuit, respectively providing the first positive output terminal, the first negative output terminal and the second negative output terminal.

Description

耳機驅動器及驅動方法Headphone Driver and Driving Method

本發明是有關於一種耳機驅動技術，且特別是有關於耳機驅動器及驅動方法，適用於驅動有兩種標準的四端點耳機裝置。 The invention relates to a headphone driving technology, and in particular to a headphone driver and a driving method, which are suitable for driving a four-terminal headphone device with two standards.

耳機裝置已是很普遍搭配電子產品，用以提供實際的聲音給使用者，其中可以產生立體音響的耳機更是普遍。 Earphone devices are commonly used with electronic products to provide actual sound to users, and earphones capable of producing stereo sound are even more common.

如一般所知，立體音響的耳機可包含對應兩個聲道的兩個喇叭。一個喇叭一般包含第一端及第二端。第一端接受電性的音訊，其波形會隨聲音而變化。第二端是接地端，其對應第一端的電性的音訊，及依照振動頻率及振幅在第一端與第二端之間構成交流訊號，以促使喇叭振膜的振動。如此，耳機的兩個喇叭的兩個第二端會連接在一起，而兩個喇叭的兩個第一端分別接受兩個聲道的音訊。因此雙聲道耳機的接收端是三端的結構。 As is generally known, a stereo headphone may include two speakers corresponding to two sound channels. A horn generally includes a first end and a second end. The first end receives electrical audio, and its waveform changes with the sound. The second end is the ground end, which corresponds to the electrical audio of the first end, and forms an AC signal between the first end and the second end according to the vibration frequency and amplitude, so as to promote the vibration of the horn diaphragm. In this way, the two second ends of the two speakers of the earphone are connected together, and the two first ends of the two speakers respectively receive audio from two channels. Therefore, the receiving end of the binaural earphone is a three-terminal structure.

耳機所要呈現的聲音是由驅動器提供。如一般的使用所知，耳機的三端插頭要***電子產品的輸出孔。耳機驅動器提供電性的聲音驅動訊號到輸出孔的三個端子，以驅動喇叭轉換成實際的聲音。 The sound to be presented by the headphones is provided by the driver. As known in general use, the three-terminal plug of the earphone should be inserted into the output hole of the electronic product. The headphone driver provides electrical sound driving signals to the three terminals of the output hole to drive the speaker into real actual sound.

兩個喇叭是由兩個驅動器分別提供不同聲道的音源。對於一個驅動器，將其對應聲道的聲音轉換成電性訊號後，由其輸出端輸出。另一個驅動器也是將其聲道的聲音轉換成電性訊號後，由其輸出端輸出。 The two speakers are provided by two drivers with different sound sources respectively. For a driver, after converting the sound of its corresponding channel into an electrical signal, it is output from its output port. The other driver also converts the sound of its channel into an electrical signal, and outputs it through its output port.

耳機裝置的進一步設計是再整合麥克風，以達到使用者的聲音傳送，而實質提升耳機裝置的功能，使得有更廣泛的使用。 The further design of the earphone device is to integrate the microphone to transmit the voice of the user, and substantially improve the function of the earphone device, so that it can be used more widely.

耳機裝置包含麥克風的架構下，其信號***端會包含四個端點。然而基於麥克風的不同配置方式，接地端點與麥克風端點的順序會不同。 Under the structure that the headphone device includes a microphone, its signal insertion end includes four terminals. However, based on different configurations of the microphones, the sequence of the ground terminal and the microphone terminal will be different.

一般而言，不同標準的耳機裝置是可以根據偵測結果，通過開關的切換進行切換連接。耳機裝置的喇叭的阻抗一般是32歐姆但也可以是其他例如16歐姆等。如此，在開關不影響耳機裝置的操作的條件下，開關的電阻效應需要很小，其因此造成開關的設計需要較大面積來減少阻抗。 Generally speaking, earphone devices of different standards can be switched and connected by switching the switch according to the detection result. The impedance of the speaker of the earphone device is generally 32 ohms but can also be other such as 16 ohms. In this way, under the condition that the switch does not affect the operation of the earphone device, the resistance effect of the switch needs to be small, which therefore requires a large area for the design of the switch to reduce the impedance.

本發明提供一種耳機驅動器及其驅動方法，開關可以使用金氧半導體(MOS)電晶體來製造，其MOS電晶體的開關可以達到小面積與低阻抗的需求。 The invention provides an earphone driver and a driving method thereof. The switch can be manufactured by using a metal oxide semiconductor (MOS) transistor, and the switch of the MOS transistor can meet the requirements of small area and low impedance.

根據一實施例，本發明提供一種耳機驅動器，用於驅動耳機裝置，其中該耳機裝置有固定位置的第一、第二、第三及第四端點。該耳機驅動器包括第一差分驅動器、第二差分驅動器、第一開關單元及第二開關單元。第一差分驅動器包含第一正驅動電路，第一負驅動電路及第二負驅動電路，分別提供第一正輸出端、第一負輸出端及第二負輸出端，該第一正輸出端接到該第一端點，該第一負輸出端及該第二負輸出端分別連接到該第三端點與該第四端點。第二差分驅動器包含第二正驅動電路，第三負驅動電路及第四負驅動電路，分別提供第二正輸出端、第三負輸出端及第四負輸出端，該第二正輸出端接到該第二端點，該第一負輸出端及該第二負輸出端分別連接到該第三端點與該第四端點。第一開關單元控制該第一差分驅動器使根據第一操作狀態或第二操作狀態分別選擇該第一負驅動電路或該第二負驅動電路輸出。第二開關單元控制該第二差分驅動器使根據該第一操作狀態或該第二操作狀態分別選擇該第三負驅動電路或該第四負驅動電路輸出。 According to an embodiment, the present invention provides an earphone driver for driving an earphone device, wherein the earphone device has first, second, third and third fixed positions Four endpoints. The headphone driver includes a first differential driver, a second differential driver, a first switch unit and a second switch unit. The first differential driver includes a first positive drive circuit, a first negative drive circuit and a second negative drive circuit, respectively providing a first positive output terminal, a first negative output terminal and a second negative output terminal, and the first positive output terminal is connected to To the first terminal, the first negative output terminal and the second negative output terminal are respectively connected to the third terminal and the fourth terminal. The second differential driver includes a second positive drive circuit, a third negative drive circuit and a fourth negative drive circuit, which respectively provide a second positive output terminal, a third negative output terminal and a fourth negative output terminal, and the second positive output terminal is connected to To the second terminal, the first negative output terminal and the second negative output terminal are respectively connected to the third terminal and the fourth terminal. The first switch unit controls the first differential driver to select the output of the first negative drive circuit or the second negative drive circuit respectively according to the first operation state or the second operation state. The second switch unit controls the second differential driver to select the output of the third negative drive circuit or the fourth negative drive circuit according to the first operation state or the second operation state respectively.

根據一實施例，本發明又提供一種耳機驅動器，用於驅動耳機裝置，其中該耳機裝置有固定位置的第一、第二、第三及第四端點。該耳機驅動器包括第一差分驅動器及第一開關單元。第一差分驅動器包含第一正輸出端，第一負輸出端及第二負輸出端，該第一正輸出端接到該第一端點。第一開關單元設置在該第一負輸出端及該第二負輸出端的回授路徑上，規劃成在第一操作狀態時致能該第一負輸出端迴授並使第一負輸出端閉迴路輸出到該第三端點，而禁能該第二負輸出端迴授並禁能該第二負輸出端開迴路輸出，以及在第二操作狀態時切換成致能該第二負輸出端迴授並使第二負輸出端閉迴路輸出到該第四端點，而禁能該第一負輸出端迴授並禁能該第一負輸出端開迴路輸出。該第一差分驅動器包括第一正電壓驅動電路、第一負電壓驅動電路及第二負電壓驅動電路，分別提供該第一正輸出端、該第一負輸出端及第二負輸出端。 According to an embodiment, the present invention further provides an earphone driver for driving an earphone device, wherein the earphone device has first, second, third and fourth terminals at fixed positions. The headphone driver includes a first differential driver and a first switch unit. The first differential driver includes a first positive output terminal, a first negative output terminal and a second negative output terminal, and the first positive output terminal is connected to the first terminal. The first switch unit is arranged on the feedback path of the first negative output terminal and the second negative output terminal, and is planned to enable the feedback of the first negative output terminal and close the first negative output terminal in the first operation state. loop output to the third terminal, while disabling the feedback of the second negative output terminal and disabling the second negative output terminal open-loop output, and switch to enable the feedback of the second negative output terminal and enable the closed-loop output of the second negative output terminal to the fourth terminal in the second operating state, while disabling the feedback of the first negative output terminal granting and disabling the open-loop output of the first negative output terminal. The first differential driver includes a first positive voltage driving circuit, a first negative voltage driving circuit and a second negative voltage driving circuit, respectively providing the first positive output terminal, the first negative output terminal and the second negative output terminal.

根據一實施例，本發明又提供一種耳機驅動方法，用於驅動耳機裝置，其中該耳機裝置有固定位置的第一、第二、第三及第四端點。該耳機驅動方法包括使用第一差分驅動器驅動該耳機裝置的第一聲道及一麥克風，該第一差分驅動器包含第一正輸出端，第一負輸出端及第二負輸出端，該第一正輸出端接到該第一端點。該耳機驅動方法還包括使用第一開關單元，設置在該第一負輸出端及該第二負輸出端的回授路徑上，規劃成在第一操作狀態時切換成使該第一負輸出端連接到該第三端點，而該第二負輸出端斷開，以及在第二操作狀態時切換成使該第二負輸出端連接到該第四端點，而該第一負輸出端斷開。該第一差分驅動器包括第一負電壓驅動電路及第二負電壓驅動電路，分別提供該第一負輸出端及第二負輸出端。 According to an embodiment, the present invention further provides an earphone driving method for driving an earphone device, wherein the earphone device has first, second, third and fourth terminals at fixed positions. The earphone driving method includes using a first differential driver to drive the first sound channel and a microphone of the earphone device, the first differential driver includes a first positive output terminal, a first negative output terminal and a second negative output terminal, the first The positive output terminal is connected to the first terminal. The headphone driving method also includes using a first switch unit, which is arranged on the feedback path of the first negative output terminal and the second negative output terminal, and is planned to be switched to connect the first negative output terminal in the first operating state. to the third terminal, while the second negative output terminal is disconnected, and switches to connect the second negative output terminal to the fourth terminal while the first negative output terminal is disconnected in the second operating state . The first differential driver includes a first negative voltage driving circuit and a second negative voltage driving circuit respectively providing the first negative output terminal and the second negative output terminal.

1、2、3、4:端點 1, 2, 3, 4: endpoints

10、50:插頭 10, 50: plug

12:麥克風 12: Microphone

14L、14R:喇叭 14L, 14R: horn

16:電阻 16: resistance

18:按鍵 18: button

20:耳機辨識電路 20: Headphone identification circuit

22:電壓量測元件 22: Voltage measuring element

24:電壓源 24: Voltage source

30A、30B、32A、32B:開關元件 30A, 30B, 32A, 32B: switching elements

40:耳機裝置40 40: headphone device 40

80L、80R:耳機驅動器 80L, 80R: headphone driver

100L、100R:差分驅動器 100L, 100R: Differential Driver

200:耳機驅動器 200: headphone driver

202A、202B、202C:開關電路 202A, 202B, 202C: switch circuit

204、204’:正驅動電路 204, 204': positive drive circuit

206A、206A’、206B、206B’:負驅動電路 206A, 206A', 206B, 206B': Negative drive circuit

208P、208N:輸出端 208P, 208N: output terminal

210:差分驅動器 210: Differential driver

212、214、216:路徑 212, 214, 216: paths

230:電阻 230: resistance

260、262:端點 260, 262: endpoint

264、266、268:開關構件 264, 266, 268: switch components

264A、264B:開關元件 264A, 264B: switching elements

266A、266B:開關元件 266A, 266B: switching elements

301、302、303、304、305、306:電晶體 301, 302, 303, 304, 305, 306: Transistor

311、312、313、314、315、316:電晶體 311, 312, 313, 314, 315, 316: Transistor

322、323、324、325:電晶體 322, 323, 324, 325: Transistor

308P、308N:節點 308P, 308N: node

318P1、318N1:節點 318P1, 318N1: node

328P0、328N0:節點 328P0, 328N0: node

400、402:開關電路 400, 402: switch circuit

圖1是依照本發明要所要考慮的兩種標準的四端點耳機裝置的插頭結構示意圖。 Fig. 1 is a four-terminal earphone device according to two standards to be considered in the present invention Schematic diagram of the plug structure.

圖2是依照本發明一實施例所考慮的CTIA耳機裝置的架構示意圖。 FIG. 2 is a schematic structural diagram of a CTIA earphone device considered according to an embodiment of the present invention.

圖3是依照本發明一實施例，圖2的耳機裝置包含耳機辨識電路的架構示意圖。 FIG. 3 is a schematic structural diagram of the earphone device in FIG. 2 including an earphone identification circuit according to an embodiment of the present invention.

圖4是依照本發明一實施例，圖3的耳機裝置的等效電路示意圖。 FIG. 4 is a schematic diagram of an equivalent circuit of the earphone device of FIG. 3 according to an embodiment of the present invention.

圖5是依照本發明一實施例，耳機裝置的等效電路示意圖。 FIG. 5 is a schematic diagram of an equivalent circuit of an earphone device according to an embodiment of the present invention.

圖6是依照本發明一實施例，圖5的耳機裝置的簡化等效電路示意圖。 FIG. 6 is a simplified equivalent circuit diagram of the earphone device shown in FIG. 5 according to an embodiment of the present invention.

圖7是依照本發明一實施例，耳機裝置與驅動器之間的整體架構示意圖。 FIG. 7 is a schematic diagram of an overall structure between an earphone device and a driver according to an embodiment of the present invention.

圖8是依照本發明一實施例，CTIA耳機裝置包括耳機辨識電路的示意圖。 FIG. 8 is a schematic diagram of a CTIA earphone device including an earphone identification circuit according to an embodiment of the present invention.

圖9是依照本發明一實施例，OMTP耳機裝置包括耳機辨識電路的示意圖。 FIG. 9 is a schematic diagram of an OMTP earphone device including an earphone identification circuit according to an embodiment of the present invention.

圖10是依照本發明一實施例，圖8的CTIA耳機裝置等效電路示意圖。 FIG. 10 is a schematic diagram of an equivalent circuit of the CTIA earphone device in FIG. 8 according to an embodiment of the present invention.

圖11是依照本發明一實施例，圖9的OMTP耳機裝置等效電路示意圖。 FIG. 11 is a schematic diagram of an equivalent circuit of the OMTP earphone device shown in FIG. 9 according to an embodiment of the present invention.

圖12是依照本發明一實施例，傳統耳機驅動器切換成為CTIA耳機裝置的整體電路示意圖。 FIG. 12 is a schematic diagram of an overall circuit of a CTIA headphone device switched from a traditional headphone driver according to an embodiment of the present invention.

圖13是依照本發明一實施例，傳統耳機驅動器切換成為OMTP耳機裝置的整體電路示意圖。 FIG. 13 is a schematic diagram of an overall circuit of a traditional headphone driver switched to an OMTP headphone device according to an embodiment of the present invention.

圖14是依照本發明一實施例，修改後耳機驅動器切換成為CTIA耳機裝置的整體電路示意圖。 FIG. 14 is a schematic diagram of an overall circuit of a modified headphone driver switched to a CTIA headphone device according to an embodiment of the present invention.

圖15是依照本發明一實施例，修改後耳機驅動器切換成為OMTP耳機裝置的整體電路示意圖。 FIG. 15 is a schematic diagram of an overall circuit of a modified headphone driver switched to an OMTP headphone device according to an embodiment of the present invention.

圖16是依照本發明一實施例，修改後耳機驅動器切換成為CTIA耳機裝置的整體電路示意圖。 FIG. 16 is a schematic diagram of an overall circuit of a modified headphone driver switched to a CTIA headphone device according to an embodiment of the present invention.

圖17是依照本發明一實施例，耳機驅動器的正輸出端的電路示意圖。 FIG. 17 is a schematic circuit diagram of a positive output terminal of an earphone driver according to an embodiment of the present invention.

圖18是依照本發明一實施例，耳機驅動器的核心電路示意圖。 FIG. 18 is a schematic diagram of a core circuit of an earphone driver according to an embodiment of the present invention.

傳統三端點耳機裝置僅可以提供立體音源，其插頭的結構包括左聲道端(L)、右聲道端(R)及接地端(GND)。要提升三端點耳機裝置的更廣泛應用功能，其可以再增加配置麥克風，使得使用者可以傳送音源。也就是三端點耳機裝置改變為四端點耳機裝置，其中的一個端點是用於連接麥克風(MIC)。配合行動電子裝置例如行動電話的需求，使得四端點耳機裝置有更廣泛的需求。 The traditional three-terminal headphone device can only provide a stereo audio source, and its plug structure includes a left channel terminal (L), a right channel terminal (R) and a ground terminal (GND). To improve the wider application of the three-terminal headphone device, it can be equipped with a microphone so that the user can transmit the audio source. That is, the three-terminal earphone device is changed into a four-terminal earphone device, one of which is used to connect a microphone (MIC). In line with the requirements of mobile electronic devices such as mobile phones, the four-terminal earphone device has a wider demand.

目前四端點耳機裝置有兩種標準，一種是OMTP標準，其通常被叫做國際標準。另一種是CTIA標準，被稱為美國標準。 OMTP標準與CTIA標準的差異在於，麥克風端點(MIC)與接地端點(GND)的順序是互換。 There are currently two standards for four-terminal earphone devices, one is the OMTP standard, which is usually called an international standard. The other is the CTIA standard, known as the American standard. The difference between the OMTP standard and the CTIA standard is that the order of the microphone terminal (MIC) and the ground terminal (GND) is interchanged.

本發明深入探究了OMTP標準與CTIA標準的差異以及其切換的機制，並且提出至少可以減少切換所需要的開關單元的尺寸，例如以MOS電晶體來達成低阻抗的開關元件，而維持元件面積的需求。 The present invention deeply explores the difference between the OMTP standard and the CTIA standard and its switching mechanism, and proposes that at least the size of the switching unit required for switching can be reduced, such as using MOS transistors to achieve low-impedance switching elements, while maintaining the size of the element area need.

以下提供多個實施例來說明本發明，但是本發明不限於所舉的實施例。 A number of examples are provided below to illustrate the present invention, but the present invention is not limited to the examples given.

本發明先深入探究了OMTP標準與CTIA標準的差異以及其偵測切換的機制。圖1是依照本發明所要考慮的兩種標準的四端點耳機裝置的插頭結構示意圖。參閱圖1，CTIA耳機裝置的插頭10的四個端點1、2、3、4的順序是左聲道端(L)、右聲道端(R)、接地端(GND)及麥克風端點(MIC)。插頭10與插頭50的四個端點1、2、3、4的位置是固定的。OMTP耳機裝置的插頭50的四個端點1、2、3、4的順序是左聲道端(L)、右聲道端(R)、麥克風端點(MIC)及接地端(GND)。二者的差異是下端兩個端點GND、MIC的作用互換。 The present invention first deeply explores the difference between the OMTP standard and the CTIA standard and the mechanism of detecting switching. Fig. 1 is a schematic diagram of the plug structure of two standard four-terminal headphone devices to be considered in accordance with the present invention. Referring to Fig. 1, the order of the four terminals 1, 2, 3 and 4 of the plug 10 of the CTIA earphone device is the left channel terminal (L), the right channel terminal (R), the ground terminal (GND) and the microphone terminal (MIC). The positions of the four terminals 1, 2, 3, 4 of the plug 10 and the plug 50 are fixed. The order of the four terminals 1, 2, 3 and 4 of the plug 50 of the OMTP earphone device is the left channel terminal (L), the right channel terminal (R), the microphone terminal (MIC) and the ground terminal (GND). The difference between the two is that the functions of the two endpoints GND and MIC at the lower end are interchanged.

圖2是依照本發明一實施例所考慮的CTIA耳機裝置的架構示意圖。參閱圖2，以CTIA耳機裝置為例，其插頭10與喇叭14L、14R及麥克風12的配置架構包括兩個聲道的喇叭14L、14R連接到左聲道端(L)、右聲道端(R)。接地端(GND)是在右聲道端(R)後面，其後是麥克風端點(MIC)。麥克風12連接在接地端(GND) 與麥克風端點(MIC)之間。另外多個按鍵18，例如按鍵(Button)A到按鍵D，允許麥克風12並聯不同電阻16，例如電阻元件R1、R2、R3、R4。 FIG. 2 is a schematic structural diagram of a CTIA earphone device considered according to an embodiment of the present invention. Referring to Fig. 2, taking the CTIA earphone device as an example, the configuration framework of its plug 10, speakers 14L, 14R and microphone 12 includes two channels of speakers 14L, 14R connected to the left channel end (L), the right channel end ( R). The ground terminal (GND) is behind the right channel terminal (R), followed by the microphone terminal (MIC). The microphone 12 is connected to the ground terminal (GND) Between the microphone endpoint (MIC). In addition, a plurality of buttons 18 , such as Button A to Button D, allow the microphone 12 to be connected in parallel with different resistors 16 , such as resistor elements R1 , R2 , R3 , and R4 .

由於CTIA耳機裝置的插頭10與OMTP耳機裝置的插頭50不同，電子裝置會設置耳機辨識電路20，連接到接地端(GND)與麥克風端點(MIC)，可以辨識出使用的耳機裝置是CTIA耳機裝置或是OMTP耳機裝置。耳機辨識電路20包括電壓量測元件22，以及電壓源24。電壓源24用以施加電壓給麥克風12，其連接在第四端點，對應CTIA耳機裝置的麥克風端點(MIC)。耳機辨識電路20可以決定所使用的耳機裝置的類型，以提供給耳機驅動器的切換。 Since the plug 10 of the CTIA earphone device is different from the plug 50 of the OMTP earphone device, the electronic device will be equipped with an earphone identification circuit 20, which is connected to the ground terminal (GND) and the microphone terminal (MIC), so that the earphone device used can be identified as a CTIA earphone. device or OMTP headset device. The earphone identification circuit 20 includes a voltage measuring element 22 and a voltage source 24 . The voltage source 24 is used to apply a voltage to the microphone 12 and is connected to the fourth terminal corresponding to the microphone terminal (MIC) of the CTIA earphone device. The headphone identification circuit 20 can determine the type of the headphone device used to provide switching of the headphone driver.

圖4是依照本發明一實施例，圖3的耳機裝置的等效電路示意圖。參閱圖4，根據圖3的耳機裝置的配置方式，對應四個端點，從電路結構來考慮，其等效電路如圖4所示。如一般可知，麥克風12有兩個端點1、2。電阻元件16、24也有兩個端點N1、N2。按鍵18是開關元件，例如通過按壓而導通，而提供所選擇的電阻元件16與麥克風12並聯。 FIG. 4 is a schematic diagram of an equivalent circuit of the earphone device of FIG. 3 according to an embodiment of the present invention. Referring to FIG. 4 , according to the configuration of the earphone device in FIG. 3 , corresponding to four terminals, the equivalent circuit is shown in FIG. 4 in terms of circuit structure. As is generally known, the microphone 12 has two endpoints 1,2. The resistive elements 16, 24 also have two terminals N1, N2. The key 18 is a switching element, which is turned on, for example by being pressed, to provide the selected resistive element 16 in parallel with the microphone 12 .

圖5是依照本發明一實施例，耳機裝置的等效電路示意圖。參閱圖5，根據圖4的電路，再把喇叭14L、14R與麥克風12等效成為電阻元件，其如圖5所示的電路，以利於分析。 FIG. 5 is a schematic diagram of an equivalent circuit of an earphone device according to an embodiment of the present invention. Referring to FIG. 5 , according to the circuit in FIG. 4 , the speakers 14L, 14R and the microphone 12 are equivalently made into resistance elements, and the circuit shown in FIG. 5 is convenient for analysis.

圖6是依照本發明一實施例，圖5的耳機裝置的簡化等效電路示意圖。參閱圖6，忽略電阻元件16的連接，耳機裝置40 的等效電路可以簡化成三個電阻元件對應兩個喇叭14L、14R及一個麥克風12。三個電阻元件共同連接到接地端GND。於此可瞭解，接地端GND是電路的低電壓端，其可以不是0V。 FIG. 6 is a simplified equivalent circuit diagram of the earphone device shown in FIG. 5 according to an embodiment of the present invention. Referring to Fig. 6, ignoring the connection of the resistance element 16, the earphone device 40 The equivalent circuit can be simplified as three resistor elements corresponding to two speakers 14L, 14R and one microphone 12 . The three resistance elements are commonly connected to the ground terminal GND. It can be understood here that the ground terminal GND is the low voltage terminal of the circuit, which may not be 0V.

圖7是依照本發明一實施例，耳機裝置與驅動器之間的整體架構示意圖。參閱圖7，耳機裝置與耳機驅動器連接。耳機驅動器對兩聲道，例如包括兩個差分驅動器100L、100R，其例如差分放大器。差分驅動器100L與差分驅動器100R接收音源以及參考電壓Vref。差分驅動器100L的正端OP_L當作正輸出端HPOUT_LP，連接喇叭14L的一端。差分驅動器100R的正端OP_R當作正輸出端HPOUT_RP，連接喇叭14R的一端。負端ON_L與負端ON_R連接在一起，提供共通的負輸出端HPOUT_N給接喇叭14L的另一端及喇叭14R的另一端，其也與麥克風12的地端連接。電壓源24提供電壓MICBIAS以驅動麥克風12。 FIG. 7 is a schematic diagram of an overall structure between an earphone device and a driver according to an embodiment of the present invention. Referring to Figure 7, the headphone device is connected to the headphone driver. The pair of headphone drivers for two channels, for example, includes two differential drivers 100L, 100R, which are, for example, differential amplifiers. The differential driver 100L and the differential driver 100R receive the sound source and the reference voltage Vref. The positive terminal OP_L of the differential driver 100L is used as a positive output terminal HPOUT_LP, which is connected to one terminal of the speaker 14L. The positive terminal OP_R of the differential driver 100R is used as a positive output terminal HPOUT_RP, which is connected to one terminal of the speaker 14R. The negative terminal ON_L and the negative terminal ON_R are connected together to provide a common negative output terminal HPOUT_N connected to the other end of the speaker 14L and the other end of the speaker 14R, which is also connected to the ground of the microphone 12 . A voltage source 24 provides a voltage MICBIAS to drive the microphone 12 .

以下描述CTIA耳機裝置與OMTP耳機裝置的連接架構。圖8是依照本發明一實施例，CTIA耳機裝置包括耳機辨識電路的示意圖。圖9是依照本發明一實施例，OMTP耳機裝置包括耳機辨識電路的示意圖。 The connection architecture between the CTIA headset device and the OMTP headset device is described below. FIG. 8 is a schematic diagram of a CTIA earphone device including an earphone identification circuit according to an embodiment of the present invention. FIG. 9 is a schematic diagram of an OMTP earphone device including an earphone identification circuit according to an embodiment of the present invention.

參閱圖8，先以CTIA耳機裝置的連接架構來看，耳機裝置40的等效電路的接地端GND是接到負輸出端HPOUT_N。喇叭14L的一端連接到正輸出端HPOUT_LP。喇叭14R的一端連接到正輸出端HPOUT_RP。麥克風12的一端是麥克風端MIC連接到電壓源24。電壓源24例如是一個電阻，其一端接收電壓VBIAS，而通過電阻以提供所要的電壓給麥克風12。 Referring to FIG. 8 , first looking at the connection structure of the CTIA earphone device, the ground terminal GND of the equivalent circuit of the earphone device 40 is connected to the negative output terminal HPOUT_N. One end of the horn 14L is connected to the positive output HPOUT_LP. One end of the horn 14R is connected to the positive output HPOUT_RP. One end of the microphone 12 is a microphone terminal MIC connected to a voltage source 24 . The voltage source 24 is, for example, a resistor, one end of which receives the voltage VBIAS, The resistor is used to provide the desired voltage to the microphone 12 .

參閱圖9，電子裝置的耳機插孔與耳機裝置的插頭的端點位置是固定。以OMTP耳機裝置的插頭50***插孔時的連接狀態來看，耳機裝置42的等效電路的接地端GND在耳機裝置42的插頭50***插孔後會連接到電壓源24。麥克風12的一端連接到負輸出端HPOUT_N。此時，OMTP耳機的型號不對應CTIA的插孔，其如後面所描述需要切換。喇叭14L的一端連接到正輸出端HPOUT_LP。喇叭14R的一端連接到正輸出端HPOUT_RP。OMTP耳機裝置的接地端GND與麥克風12的麥克風端MIC相對於圖8的CTIA耳機裝置40，在插頭位置是相反，如圖1所示。 Referring to FIG. 9 , the end positions of the earphone jack of the electronic device and the plug of the earphone device are fixed. From the connection state when the plug 50 of the OMTP earphone device is inserted into the jack, the ground terminal GND of the equivalent circuit of the earphone device 42 will be connected to the voltage source 24 after the plug 50 of the earphone device 42 is inserted into the jack. One end of the microphone 12 is connected to the negative output terminal HPOUT_N. At this time, the model of the OMTP headset does not correspond to the CTIA jack, which needs to be switched as described later. One end of the horn 14L is connected to the positive output HPOUT_LP. One end of the horn 14R is connected to the positive output HPOUT_RP. The ground terminal GND of the OMTP earphone device and the microphone end MIC of the microphone 12 are opposite to the CTIA earphone device 40 in FIG. 8 , as shown in FIG. 1 .

在實際操作上，當耳機裝置42***插孔後，電子裝置需要偵測耳機裝置42是CTIA或是OMTP。偵測機制可以根據圖8與圖9的連接差異來判斷。例如，在VBIAS與HPOUT_N端點施加不同電壓值，而產生電壓差(voltage bias)，跨過麥克風12的等效電阻。就圖8而言，HPOUT_LP端點或HPOUT_RP端點的電壓會實質等於在HPOUT_N端點的電壓。因此，可以判斷耳機裝置40是CTIA。就圖9而言，如果OMTP的耳機裝置42***後，麥克風12是在下端與HPOUT_N端點連接，因此HPOUT_N端點與HPOUT_LP端點或HPOUT_RP端點之間，因為麥克風12的等效電阻而產生電壓差。也就是，在HPOUT_LP端點或HPOUT_RP端點的電壓實質不等於在HPOUT_N端點的電壓。如此，此狀態可以判斷耳機裝置42是OMTP型。 In actual operation, when the earphone device 42 is inserted into the jack, the electronic device needs to detect whether the earphone device 42 is CTIA or OMTP. The detection mechanism can be judged according to the connection difference between FIG. 8 and FIG. 9 . For example, different voltage values are applied to the terminals VBIAS and HPOUT_N to generate a voltage bias across the equivalent resistance of the microphone 12 . Referring to FIG. 8, the voltage at the HPOUT_LP terminal or the HPOUT_RP terminal will be substantially equal to the voltage at the HPOUT_N terminal. Therefore, it can be judged that the earphone device 40 is a CTIA. With regard to FIG. 9 , if the earphone device 42 of OMTP is plugged in, the microphone 12 is connected to the HPOUT_N terminal at the lower end, so between the HPOUT_N terminal and the HPOUT_LP terminal or HPOUT_RP terminal, an equivalent resistance of the microphone 12 is generated. Voltage difference. That is, the voltage at the HPOUT_LP terminal or the HPOUT_RP terminal is not substantially equal to the voltage at the HPOUT_N terminal. In this way, it can be judged that the headphone device 42 is of the OMTP type in this state.

圖10是依照本發明一實施例，圖8的CTIA耳機裝置等效電路示意圖。圖11是依照本發明一實施例，圖9的OMTP耳機裝置等效電路示意圖。 FIG. 10 is a schematic diagram of an equivalent circuit of the CTIA earphone device in FIG. 8 according to an embodiment of the present invention. FIG. 11 is a schematic diagram of an equivalent circuit of the OMTP earphone device shown in FIG. 9 according to an embodiment of the present invention.

參閱圖10與圖11，由於OMTP耳機裝置與CTIA耳機裝置的結構不同，例如，電子裝置是採用CTIA標準的插孔，則OMTP耳機裝置***CTIA的插孔是無法工作，其需要適當的切換。圖10與圖11的等效電路是對應CTIA標準與OMTP標準的實際要達到的工作電路。 Referring to Fig. 10 and Fig. 11, since the structure of the OMTP earphone device and the CTIA earphone device are different, for example, the electronic device adopts the jack of CTIA standard, then the OMTP earphone device cannot work when inserted into the CTIA jack, and it needs to be switched appropriately. The equivalent circuits in FIG. 10 and FIG. 11 are actual working circuits corresponding to the CTIA standard and the OMTP standard.

圖12是依照本發明一實施例，傳統耳機驅動器切換成為CTIA耳機裝置的整體電路示意圖。參閱圖12，耳機驅動器增加開關單元設置在負輸出端，例如包括開關元件30A、30B，其例如配合CTIA標準，開關元件30A是斷開，而開關元件30B是導通。耳機驅動器80L的正輸出端HPOUT_LP是驅動左聲道的喇叭14L。耳機驅動器80R的正輸出端HPOUT_RP是驅動右聲道的喇叭14R。耳機驅動器80L、80R例如是差分放大器。 FIG. 12 is a schematic diagram of an overall circuit of a CTIA headphone device switched from a traditional headphone driver according to an embodiment of the present invention. Referring to FIG. 12 , the headphone driver is provided with a switch unit at the negative output terminal, for example, including switch elements 30A and 30B, which conform to CTIA standards, for example, the switch element 30A is turned off, and the switch element 30B is turned on. The positive output HPOUT_LP of the headphone driver 80L drives the left channel speaker 14L. The positive output HPOUT_RP of the headphone driver 80R drives the right channel speaker 14R. The headphone drivers 80L, 80R are, for example, differential amplifiers.

因應CTIA標準與OMTP標準的差異，耳機驅動器80L、80R的負輸出端，以及電壓源的麥克風端點MIC需要適當切換。在一實施例，開關元件30A與開關元件30B是連接到耳機驅動器80L、80R的負輸出端HPOUT_LN、HPOUT_RN。開關元件30A的連接路徑是連接到麥克風端點MIC。開關元件30B的連接路徑是連接到接地端點GND。開關元件32A的連接路徑是連接到麥克風端點MIC。開關元件32B的連接路徑是連接到接地端點GND。 Due to the differences between the CTIA standard and the OMTP standard, the negative output terminals of the headphone drivers 80L and 80R, and the microphone terminal MIC of the voltage source need to be properly switched. In one embodiment, the switching element 30A and the switching element 30B are connected to the negative output terminals HPOUT_LN, HPOUT_RN of the headphone drivers 80L, 80R. The connection path of the switching element 30A is connected to the microphone terminal MIC. The connection path of the switch element 30B is connected to the ground terminal GND. The connection path of the switch element 32A is connected to the microphone terminal MIC. The connection path of the switching element 32B is connected to the ground terminal GND.

當要與CTIA耳機裝置40連接，開關元件30A、32A是斷開，而開關元件30B、32B是導通，因此負輸出端HPOUT_LN、HPOUT_RN連接到接地端點GND，即是端點3。端點4是當作麥克風端點MIC，用以接收電壓源。 When connecting to the CTIA earphone device 40 , the switch elements 30A, 32A are turned off, and the switch elements 30B, 32B are turned on, so the negative output terminals HPOUT_LN, HPOUT_RN are connected to the ground terminal GND, which is terminal 3 . Terminal 4 is used as a microphone terminal MIC to receive a voltage source.

參閱圖13，以OMTP耳機裝置42的連接，開關元件30B、32B是斷開，而開關元件30A、32A是導通，因此負輸出端HPOUT_LN、HPOUT_RN連接到端點4，其當作接地端點GND。端點3是麥克風端點MIC接收電壓源。 Referring to FIG. 13 , with the connection of the OMTP earphone device 42, the switch elements 30B and 32B are turned off, and the switch elements 30A and 32A are turned on, so the negative output terminals HPOUT_LN and HPOUT_RN are connected to terminal 4, which is regarded as the ground terminal GND . Terminal 3 is the microphone terminal MIC receiving voltage source.

關於圖12與圖13的切換機制，其可以達到CTIA耳機裝置40與OMTP耳機裝置42的切換，其中耳機裝置的阻抗例如是32歐姆。為了不影響耳機裝置的性能，開關元件的阻抗相對於耳機裝置的阻抗需可忽略的小。然而以圖12與圖13的切換機制來考量，其開關元件會需要大面積的設計，以降低開關元件的阻抗。由於開關元件是直接切換耳機驅動器的輸出信號，開關元件的設計不容易達到低阻抗的需求，其一般會採用大面積的方式來降低阻抗。 Regarding the switching mechanism in FIG. 12 and FIG. 13 , it can achieve switching between the CTIA earphone device 40 and the OMTP earphone device 42 , wherein the impedance of the earphone device is, for example, 32 ohms. In order not to affect the performance of the earphone device, the impedance of the switching element needs to be negligibly small relative to the impedance of the earphone device. However, considering the switching mechanism of FIG. 12 and FIG. 13 , the switch element needs to be designed with a large area to reduce the impedance of the switch element. Since the switching element directly switches the output signal of the headphone driver, the design of the switching element is not easy to meet the requirement of low impedance, and generally a large area is used to reduce the impedance.

本發明在一實施例，提出一種切換機制，允許開關元件可以此用一般小尺寸的MOS元件來達成。 In one embodiment of the present invention, a switching mechanism is proposed, which allows the switching element to be realized by a generally small-sized MOS element.

圖14是依照本發明一實施例，修改後耳機驅動器切換成為CTIA耳機裝置的整體電路示意圖。參閱圖14，耳機驅動器200的一個聲道包括一差分驅動器210例如根據差分放大器的正極電路與負極電路修改為包含正驅動電路204、負驅動電路206A及負驅動電路206B。以下以左聲道的差分驅動器210為例來說明，而右聲道的驅動器是相同，不再另外描述。 FIG. 14 is a schematic diagram of an overall circuit of a modified headphone driver switched to a CTIA headphone device according to an embodiment of the present invention. Referring to Fig. 14, one channel of the headphone driver 200 includes a differential driver 210, for example, modified to include a positive drive circuit 204, a negative drive circuit 206A and a negative drive circuit 206B. The following uses the differential driver 210 of the left channel as an example for illustration, but the driver of the right channel is the same, and will not be further described.

正驅動電路204用以最後提供正輸出電壓HPOUT_LP，通過路徑212連接到端點1。負驅動電路206A是與正驅動電路204對稱的電路，用以最後提供一個負輸出電壓HPOUT_LN0。在一實施例，負驅動電路206B與負驅動電路206A可以是相似的電路但是分別啟動，其中在兩個電路中與輸入及輸出的兩個電壓端連接的電晶體可以共用。共用的電晶體例如是圖18的電晶體311、316，後面會較詳細描述。也就是說，在電路硬體上，負驅動電路206B與負驅動電路206A是相似的電路，而例如可以有一部分電晶體是共用的。負驅動電路206A與負驅動電路206B是分別根據CTIA或是OMTP的偵測結果而啟動，以提供對應地負輸出電壓HPOUT_LN0(圖14)或是負輸出電壓HPOUT_LN1(圖15)。 The positive driving circuit 204 is used to finally provide a positive output voltage HPOUT_LP, which is connected to the terminal 1 through the path 212 . The negative driving circuit 206A is a circuit symmetrical to the positive driving circuit 204, and is used to finally provide a negative output voltage HPOUT_LN0. In one embodiment, the negative driving circuit 206B and the negative driving circuit 206A can be similar circuits but activated separately, wherein the transistors connected to the two voltage terminals of the input and output in the two circuits can be shared. The shared transistors are, for example, the transistors 311 and 316 in FIG. 18 , which will be described in detail later. That is to say, in terms of circuit hardware, the negative driving circuit 206B and the negative driving circuit 206A are similar circuits, and for example, some transistors may be shared. The negative driving circuit 206A and the negative driving circuit 206B are respectively activated according to the detection result of CTIA or OMTP to provide corresponding negative output voltage HPOUT_LN0 ( FIG. 14 ) or negative output voltage HPOUT_LN1 ( FIG. 15 ).

另外差分驅動器210還包括開關單元由開關電路202A與開關電路202B分別控制負驅動電路206A與負驅動電路206B迴路的開啟或關閉。開關電路202A與開關電路202B是互相相反的狀態，僅維持其中一者導通而另一者斷開。開關電路202A與開關電路202B例如是設置在差分放大器的回授路徑上，可以控制回授路徑的導通或是斷開。CTIA耳機裝置40與OMTP耳機裝置42的接地端GND是獨立分別由負輸出電壓HPOUT_LN0與負輸出電壓HPOUT_LN1提供。負輸出電壓HPOUT_LN0會通過路徑214連接到端點3，對應CTIA耳機裝置40的接地端點GND。負輸出電壓HPOUT_LN1會通過路徑216連接到端點4，對應CTIA耳機裝置40的麥克風端MIC，但是路徑214導通時路徑216是斷開的。 In addition, the differential driver 210 also includes a switch unit, and the switch circuit 202A and the switch circuit 202B respectively control the opening or closing of the loop of the negative driving circuit 206A and the negative driving circuit 206B. The switch circuit 202A and the switch circuit 202B are in opposite states, and only one of them is turned on while the other is turned off. The switch circuit 202A and the switch circuit 202B are, for example, disposed on the feedback path of the differential amplifier, and can control the conduction or disconnection of the feedback path. The ground terminals GND of the CTIA earphone device 40 and the OMTP earphone device 42 are independently provided by the negative output voltage HPOUT_LN0 and the negative output voltage HPOUT_LN1 respectively. The negative output voltage HPOUT_LN0 is connected to the terminal 3 through the path 214 , corresponding to the ground terminal GND of the CTIA earphone device 40 . negative output The voltage HPOUT_LN1 is connected to the terminal 4 through the path 216 , corresponding to the microphone terminal MIC of the CTIA earphone device 40 , but the path 216 is turned off when the path 214 is turned on.

圖14是對應CTIA耳機裝置40的連接，而負輸出電壓HPOUT_LN0是耳機驅動器200的負驅動電路206A獨立提供，迴授迴路由開關電路202A的控制而導通。負驅動電路206B的迴授迴路受開關電路202B的控制而斷開。 14 is the connection corresponding to the CTIA earphone device 40, and the negative output voltage HPOUT_LN0 is independently provided by the negative driving circuit 206A of the earphone driver 200, and the feedback loop is turned on by the control of the switch circuit 202A. The feedback loop of the negative driving circuit 206B is turned off under the control of the switch circuit 202B.

圖15是依照本發明一實施例，修改後耳機驅動器切換成為OMTP耳機裝置的整體電路示意圖。參閱圖15，對應OMTP耳機裝置42的連接，開關電路202A是切換成斷開的狀態，而開關電路202B是切換成導通狀態。如此，路經214是由開關電路202A斷開。而路徑216是開關電路202B導通，以提供負輸出電壓HPOUT_LN1到端點4，其對應OMTP耳機裝置42的接地端GND。端點3是對應麥克風端點MIC，接收麥克風驅動電壓。 FIG. 15 is a schematic diagram of an overall circuit of a modified headphone driver switched to an OMTP headphone device according to an embodiment of the present invention. Referring to FIG. 15 , corresponding to the connection of the OMTP earphone device 42 , the switch circuit 202A is switched to an off state, and the switch circuit 202B is switched to an on state. In this way, the path 214 is disconnected by the switch circuit 202A. The path 216 is turned on by the switch circuit 202B to provide the negative output voltage HPOUT_LN1 to the terminal 4 , which corresponds to the ground terminal GND of the OMTP earphone device 42 . Terminal 3 is corresponding to the microphone terminal MIC, which receives the microphone driving voltage.

由於負驅動電路206A與負驅動電路206B是耳機驅動器200中的獨立輸出，負輸出電壓HPOUT_LN0與負輸出電壓HPOUT_LN1不是共用的狀態。如此的電路，開關電路202A與開關電路202B可以使用一般的MOS元件製造，其阻抗只需相對於迴授電阻阻抗可忽略的小，其結果會使元件面積足夠小。開關電路202A與開關電路202B的製造與MOS電晶體與驅動電路的製造流程相容，不會實質增加製造的困難度。 Since the negative driving circuit 206A and the negative driving circuit 206B are independent outputs of the headphone driver 200 , the negative output voltage HPOUT_LN0 and the negative output voltage HPOUT_LN1 are not in a common state. In such a circuit, the switch circuit 202A and the switch circuit 202B can be manufactured using common MOS components, and their impedances need only be negligibly small compared to the impedance of the feedback resistors, resulting in a sufficiently small component area. The manufacturing of the switch circuit 202A and the switch circuit 202B is compatible with the manufacturing process of the MOS transistor and the driving circuit, and does not substantially increase the difficulty of manufacturing.

開關電路202A與開關電路202B的電路結構，可以依照實際需要而設計，在一實施例是不需要特別限制。 The circuit structures of the switch circuit 202A and the switch circuit 202B can be designed according to actual needs, and there is no special limitation in one embodiment.

圖16是依照本發明一實施例，修改後耳機驅動器切換成為CTIA耳機裝置的整體電路示意圖。參閱圖16，在進一步考慮耳機的性能，耳機裝置是在待機狀態(standby mode)，在正輸出端可能會有電流經由電阻230回灌訊號輸入端導致漏電，會再設置一個開關電路202C，以在待機狀態時關閉路徑212。然而，在一般的情形下，正輸出電壓HPOUT_LP是會隨信號改變(signal-dependent)。此開關電路202C的CMOS元件的基板(bulk)在操作狀態時也連接到正輸出電壓HPOUT_LP，以避免在操作狀態下由於基體效應(body effect)所產生的非線性現象。另外，在待機狀態時，基板施加另一穩定電壓，以避免漏電。另外在一實施例，CMOS元件的開關電路中的NMOS例如也可以採用在深N型井區(deep N-well)中形成。 FIG. 16 is a schematic diagram of an overall circuit of a modified headphone driver switched to a CTIA headphone device according to an embodiment of the present invention. Referring to Figure 16, further considering the performance of the earphone, the earphone device is in standby mode, there may be current at the positive output terminal through the resistor 230 to feed back the signal input end to cause leakage, and a switch circuit 202C will be set to Path 212 is closed during standby. However, under normal circumstances, the positive output voltage HPOUT_LP is signal-dependent. The bulk of the CMOS device of the switching circuit 202C is also connected to the positive output voltage HPOUT_LP in the operating state, so as to avoid the non-linear phenomenon caused by the body effect in the operating state. In addition, in the standby state, another stable voltage is applied to the substrate to avoid leakage. In addition, in an embodiment, the NMOS in the switching circuit of the CMOS element can also be formed in a deep N-well region (deep N-well).

圖17是依照本發明一實施例，耳機驅動器的正輸出端的電路示意圖。參閱圖17，耳機驅動器200有正輸出端208P與負輸出端208N。負輸出端208N如前述對應耳機裝置的接地端GND端連接。正輸出端208P對應操作狀態或是待機狀態，是由開關電路202C控制。開關電路202C例如設置在回授路徑上。 FIG. 17 is a schematic circuit diagram of a positive output terminal of an earphone driver according to an embodiment of the present invention. Referring to FIG. 17 , the headphone driver 200 has a positive output terminal 208P and a negative output terminal 208N. The negative output terminal 208N is connected to the ground terminal GND of the headphone device as described above. The positive output terminal 208P corresponds to the operating state or the standby state, which is controlled by the switch circuit 202C. The switch circuit 202C is, for example, disposed on the feedback path.

在一實施例，開關電路202C的架構例如是由三個開關構件264、266、268所構成，連接在正輸出端208P與電阻230之間。開關構件264例如是由兩個CMOS開關元件264A、264B所構成。根據切換狀態，開關元件264A與開關元件264B僅會有一個是開啟。開關構件266例如是兩個CMOS開關元件266A、266B所構成。根據切換狀態，開關元件266A與開關元件266B僅會有一個是開啟。如一般方式，CMOS開關元件例如是NMOS電晶體與PMOS電晶體所組成，其中NMOS電晶體是在深N型井區中形成。開關構件268是單一個CMOS開關元件。 In one embodiment, the structure of the switch circuit 202C is composed of three switch components 264 , 266 , 268 , which are connected between the positive output terminal 208P and the resistor 230 . The switch member 264 is composed of, for example, two CMOS switch elements 264A, 264B. According to the switching state, only one of the switching element 264A and the switching element 264B is turned on. The switch member 266 is, for example, formed by two CMOS switch elements 266A, 266B. become. According to the switching state, only one of the switching element 266A and the switching element 266B is turned on. As usual, the CMOS switching element is composed of NMOS transistors and PMOS transistors, wherein the NMOS transistors are formed in the deep N-well region. The switching member 268 is a single CMOS switching element.

正輸出端208P連接到CMOS開關元件264B、CMOS開關元件266A、CMOS開關元件268。CMOS開關元件264的端點260接收系統低電壓。另外，CMOS開關元件266B的端點262接收另一電壓。開關元件268的NMOS電晶體，其基板(bulk)可經由開關元件264B連接至正輸出端208P或由開關元件264A連接至端點接收系統低電壓，例如最低電位GND。開關元件268的PMOS電晶體，其基板(bulk)可經由開關元件266A連接至正輸出端208P或由開關元件266B連接至端點262接收另一電壓，例如某最高電位VDD。開關元件268的NMOS電晶體，其基板可經由開關元件264B連接至正輸出端208P和開關元件268的PMOS電晶體的基板可經由266A連接至正輸出端208P。如此，可於訊號導通時有效去除基體效應(body effect)所導致的開關元件268的等效阻抗隨訊號大小變化而變化所導致的聲音失真。 Positive output terminal 208P is connected to CMOS switching element 264B, CMOS switching element 266A, CMOS switching element 268 . Terminal 260 of CMOS switching element 264 receives the system low voltage. In addition, terminal 262 of CMOS switching element 266B receives another voltage. The bulk of the NMOS transistor of the switching element 268 can be connected to the positive output terminal 208P via the switching element 264B or connected to a terminal receiving the system low voltage through the switching element 264A, such as the lowest potential GND. The bulk of the PMOS transistor of the switching element 268 can be connected to the positive output terminal 208P through the switching element 266A or connected to the terminal 262 through the switching element 266B to receive another voltage, such as a certain highest potential VDD. The substrate of the NMOS transistor of switching element 268 can be connected to positive output terminal 208P via switching element 264B and the substrate of the PMOS transistor of switching element 268 can be connected to positive output terminal 208P via 266A. In this way, the sound distortion caused by the change of the equivalent impedance of the switch element 268 caused by the body effect can be effectively removed when the signal is turned on.

於此，開關電路202C的實際電路僅是一實施例，其可以依實際需要配合設置，而達到所需要的功能，不再進一步詳細說明。 Herein, the actual circuit of the switch circuit 202C is only an embodiment, which can be configured according to actual needs to achieve the required functions, and will not be further described in detail.

圖18是依照本發明一實施例，耳機差分驅動器的核心電路示意圖。參閱圖18，在一實施例，對應一個聲道的核心電路包括差分驅動器210例如是差分放大器的結構，其核心電路例如由多個P型電晶體與多個N型電晶體構成，其在半導體製造上是CMOS電路結構。差分驅動器210的核心電路結構包括正驅動電路204’及兩個負驅動電路206A’、206B’。正驅動電路204’例如包括三個PMOS電晶體301、302、303以及三個NMOS電晶體304、305、306串接。負驅動電路206A’也是三個PMOS電晶體311、312、313以及三個NMOS電晶體314、315、316串接。正驅動電路204’及負驅動電路206A’是差分放大器的結構，兩端是連接於系統高電壓與系統低電壓之間。 FIG. 18 is a schematic diagram of a core circuit of an earphone differential driver according to an embodiment of the present invention. Referring to Figure 18, in one embodiment, the core circuit package corresponding to a channel The structure including the differential driver 210 is, for example, a differential amplifier, and its core circuit is composed of, for example, a plurality of P-type transistors and a plurality of N-type transistors, which is a CMOS circuit structure in semiconductor manufacturing. The core circuit structure of the differential driver 210 includes a positive driving circuit 204' and two negative driving circuits 206A', 206B'. The positive driving circuit 204' includes, for example, three PMOS transistors 301, 302, 303 and three NMOS transistors 304, 305, 306 connected in series. The negative drive circuit 206A' is also three PMOS transistors 311, 312, 313 and three NMOS transistors 314, 315, 316 connected in series. The positive driving circuit 204' and the negative driving circuit 206A' are differential amplifiers, both ends of which are connected between the system high voltage and the system low voltage.

根據圖14到圖17所設置的負驅動電路206B’及開關電路202A、202B、202C，其也是由多個PMOS電晶體與多個NMOS電晶體組成。 The negative drive circuit 206B' and the switch circuits 202A, 202B, and 202C arranged according to FIGS. 14 to 17 are also composed of a plurality of PMOS transistors and a plurality of NMOS transistors.

關於負驅動電路206B’的設置，其複製負驅動電路206A’的一部分電路而構成另一組與負驅動電路206A’相似的電路結構，對應圖15中的負驅動電路206B的作用。例如將負驅動電路206A’的電晶體312、313、314、315複製成電晶體322、323、324、325。負驅動電路206B’加上與負驅動電路206A’共用的電晶體311與電晶體316可以構成與負驅動電路206A’相似的電路，其對應圖15中的負驅動電路206B的作用。另外負驅動電路206A’也對應圖14中的負驅動電路206A的作用。如此，正驅動電路204’的輸出包括在一對節點308P、308N，用於後續產生正輸出電壓。負驅動電路206A’的輸出包括一對節點318P1、318N1，用於後續產生一個負輸出電壓。另一個負驅動電路206B’的輸出包括在一對節點328P0、328N0，用於後續產生另一個負輸出電壓。開關電路400與開關電路402構成開關單元，達成開關電路前面描述的開關電路202A、202B、202C的控制相符合。 Regarding the setting of the negative drive circuit 206B', it copies a part of the negative drive circuit 206A' to form another group of circuit structures similar to the negative drive circuit 206A', corresponding to the role of the negative drive circuit 206B in Figure 15 . For example, the transistors 312, 313, 314, 315 of the negative drive circuit 206A' are replicated as transistors 322, 323, 324, 325. The negative drive circuit 206B' plus the transistor 311 and transistor 316 shared with the negative drive circuit 206A' can constitute a circuit similar to the negative drive circuit 206A', which corresponds to the negative drive circuit 206B in FIG. 15 . In addition, the negative drive circuit 206A' also corresponds to the negative drive circuit 206A in FIG. 14 . As such, the output of the positive driver circuit 204' is included at a pair of nodes 308P, 308N for subsequent generation of a positive output voltage. The output of the negative drive circuit 206A' includes a pair of nodes 318P1, 318N1 for subsequent generation of a negative output voltage. The output of the other negative driver circuit 206B' is included at a pair of nodes 328P0, 328N0 for subsequent generation of another negative output voltage. The switch circuit 400 and the switch circuit 402 constitute a switch unit, and the control of the switch circuits 202A, 202B, and 202C described above is consistent with the switch circuit.

於此，差分驅動器210在整體架構整體包括在核心電路外圍的周邊控制電路，其詳細的電路設計於此不再更詳細描述，可以依照所要達到的功能的設計達成。 Here, the overall structure of the differential driver 210 includes peripheral control circuits around the core circuit, and its detailed circuit design will not be described in detail here, and can be achieved according to the design of the desired function.

綜合前面的描述，本發明在驅動器的設計，其負輸出端是規劃成兩個獨立的兩個負輸出電壓，因應CTIA標準與OMTP標準分別獨立提供給接地端點GND的電壓，其間的切換由開關單元切換。另外例如前面圖16與圖17的描述，在考慮耳機裝置在待機狀態可能發生漏電的情形，可以在正輸出電壓的回授路徑上也增加開關電路202C。此開關電路202C的CMOS元件的基板在操作狀態時也可以連接到正輸出電壓HPOUT_LP，以避免在操作狀態下由於基體效應(body effect)所產生的非線性現象，而導致聲音失真。另外，在待機狀態時，基板施加另一穩定電壓，以避免漏電。 Based on the foregoing description, in the design of the driver of the present invention, its negative output terminal is planned to be two independent negative output voltages, which are independently provided to the ground terminal GND voltage in response to the CTIA standard and the OMTP standard, and the switching between them is performed by Switch unit switching. In addition, for example, as described above in FIG. 16 and FIG. 17 , in consideration of the possible leakage of the earphone device in the standby state, a switch circuit 202C may also be added on the feedback path of the positive output voltage. The substrate of the CMOS element of the switch circuit 202C can also be connected to the positive output voltage HPOUT_LP in the operating state, so as to avoid the sound distortion caused by the non-linear phenomenon caused by the body effect in the operating state. In addition, in the standby state, another stable voltage is applied to the substrate to avoid leakage.

1、2、3、4:端點 1, 2, 3, 4: endpoints

14L、14R:喇叭 14L, 14R: horn

40:耳機裝置 40: Headphone device

200:耳機驅動器 200: headphone driver

202A、202B:開關電路 202A, 202B: switch circuit

204:正驅動電路 204: Positive drive circuit

206A、206B:負驅動電路 206A, 206B: Negative drive circuit

210:差分驅動器 210: Differential driver

212、214、216:路徑 212, 214, 216: paths

Claims

一種耳機驅動器，用於驅動耳機裝置，其中該耳機裝置有固定位置的第一、第二、第三及第四端點，該耳機驅動器包括：第一差分驅動器，包含第一正驅動電路，第一負驅動電路及第二負驅動電路，分別提供第一正輸出端、第一負輸出端及第二負輸出端，該第一正輸出端接到該第一端點，該第一負輸出端及該第二負輸出端分別連接到該第三端點與該第四端點；第二差分驅動器，包含第二正驅動電路，第三負驅動電路及第四負驅動電路，分別提供第二正輸出端、第三負輸出端及第四負輸出端，該第二正輸出端接到該第二端點，該第三負輸出端及該第四負輸出端分別連接到該第三端點與該第四端點；第一開關單元，控制該第一差分驅動器使根據第一操作狀態或第二操作狀態分別選擇該第一負驅動電路或該第二負驅動電路；以及第二開關單元，控制該第二差分驅動器使根據該第一操作狀態或該第二操作狀態分別選擇該第三負驅動電路或該第四負驅動電路。 An earphone driver is used to drive an earphone device, wherein the earphone device has first, second, third and fourth terminals at fixed positions, the earphone driver includes: a first differential driver, including a first positive drive circuit, a second A negative drive circuit and a second negative drive circuit respectively provide a first positive output terminal, a first negative output terminal and a second negative output terminal, the first positive output terminal is connected to the first terminal, and the first negative output terminal The terminal and the second negative output terminal are respectively connected to the third terminal and the fourth terminal; the second differential driver includes a second positive drive circuit, a third negative drive circuit and a fourth negative drive circuit, respectively providing the first Two positive output terminals, a third negative output terminal and a fourth negative output terminal, the second positive output terminal is connected to the second terminal, the third negative output terminal and the fourth negative output terminal are respectively connected to the third terminal and the fourth terminal; a first switch unit, controlling the first differential driver to select the first negative drive circuit or the second negative drive circuit according to the first operation state or the second operation state; and the second A switch unit controls the second differential driver to select the third negative drive circuit or the fourth negative drive circuit according to the first operation state or the second operation state respectively.

如請求項1所述的耳機驅動器，其中該耳機裝置的該第一端點與該第二端點分別連接到二個喇叭，該第三端點與該第四端點之間設置有一麥克風，其中在該第一操作狀態時該第三端點是該麥克風的負極端，在該第二操作狀態時該第四端點是該麥克風的負極端。 The headphone driver as claimed in item 1, wherein the first end point and the second end point of the headphone device are respectively connected to two speakers, and a microphone is arranged between the third end point and the fourth end point, Wherein in the first operating state the third terminal point is the negative terminal of the microphone, and the fourth terminal is the negative terminal of the microphone in the second operating state.

如請求項2所述的耳機驅動器，其中該第一差分驅動器與該第二差分驅動器的每一個更包括開關電路，設置在該第一正輸出端與該第二正輸出端的回授路徑上，用以在待機狀態下斷開，且施加一穩定電壓。 The headphone driver as claimed in claim 2, wherein each of the first differential driver and the second differential driver further includes a switch circuit disposed on a feedback path between the first positive output terminal and the second positive output terminal, It is used to disconnect in standby mode and apply a stable voltage.

如請求項3所述的耳機驅動器，其中該開關電路在操作狀態時，該開關電路的PMOS電晶體的基板連接到對應的該第一與第二正輸出端，去除該開關電路中與該第一與第二正輸出端連接的開關元件的等效阻抗隨在該第一與第二差分驅動器的訊號大小變化而變化所導致的失真。 The headphone driver as described in claim 3, wherein when the switch circuit is in an operating state, the substrate of the PMOS transistor of the switch circuit is connected to the corresponding first and second positive output terminals, and the first and second positive output terminals in the switch circuit are removed. A distortion caused by the variation of the equivalent impedance of the switching element connected with the second positive output terminal as the magnitude of the signal between the first and second differential drivers varies.

如請求項1所述的耳機驅動器，其中該第一開關單元與該第二開關單元分別包含多個N型電晶體與多個P型電晶體，其中該多個N型電晶體是包含深N形井區的基底。 The headphone driver as claimed in item 1, wherein the first switch unit and the second switch unit respectively comprise a plurality of N-type transistors and a plurality of P-type transistors, wherein the plurality of N-type transistors comprise deep N The base of the shaped well area.

一種耳機驅動器，用於驅動耳機裝置，其中該耳機裝置有固定位置的第一、第二、第三及第四端點，該耳機驅動器包括：第一差分驅動器，包含第一正輸出端，第一負輸出端及第二負輸出端，該第一正輸出端接到該第一端點；以及第一開關單元，設置在該第一負輸出端及該第二負輸出端的回授路徑上，規劃成在第一操作狀態時致能該第一負輸出端迴授並使第一負輸出端閉迴路輸出到該第三端點，而禁能該第二負輸出端迴授並禁能該第二負輸出端開迴路輸出，以及在第二操作狀態時切換成致能該第二負輸出端迴授並使第二負輸出端閉迴路輸出到該第四端點，而禁能該第一負輸出端迴授並禁能該第一負輸出端開迴路輸出，其中該第一差分驅動器包括第一正電壓驅動電路、第一負電壓驅動電路及第二負電壓驅動電路，分別提供該第一正輸出端、該第一負輸出端及第二負輸出端。 An earphone driver is used to drive an earphone device, wherein the earphone device has first, second, third and fourth terminals at fixed positions, the earphone driver includes: a first differential driver, including a first positive output terminal, a second a negative output terminal and a second negative output terminal, the first positive output terminal is connected to the first terminal; and a first switch unit is arranged on the feedback path of the first negative output terminal and the second negative output terminal , it is planned to enable the feedback of the first negative output terminal and make the closed-loop output of the first negative output terminal to the third terminal in the first operation state, while disabling the second negative output terminal Feedback at the output terminal and disable the open-loop output of the second negative output terminal, and switch to enable the feedback at the second negative output terminal and enable the closed-loop output of the second negative output terminal to the fourth in the second operating state terminal, and disable the feedback of the first negative output terminal and disable the open-loop output of the first negative output terminal, wherein the first differential driver includes a first positive voltage drive circuit, a first negative voltage drive circuit and a second The negative voltage driving circuit respectively provides the first positive output terminal, the first negative output terminal and the second negative output terminal.

如請求項6所述的耳機驅動器，其中該第一開關單元依照該第一操作狀態或該第二操作狀態啟動該第一負電壓驅動電路與該第二負電壓驅動電路的其一。 The headphone driver as claimed in claim 6, wherein the first switch unit activates one of the first negative voltage driving circuit and the second negative voltage driving circuit according to the first operation state or the second operation state.

如請求項7所述的耳機驅動器，還包括：第二差分驅動器，包含第二正輸出端，第三負輸出端及第四負輸出端，該第二正輸出端接到該第二端點；以及第二開關單元，設置在該第三負輸出端及該第四負輸出端的回授路徑上，規劃成在該第一操作狀態時致能該第三負輸出端迴授並使第三負輸出端閉迴路輸出到該第三端點，而禁能該第四負輸出端迴授並禁能該第四負輸出端開迴路輸出，以及在該第二操作狀態時致能該第四負輸出端迴授並使第四負輸出端閉迴路輸出到該第四端點，而禁能該第三負輸出端迴授並禁能該第三負輸出端開迴路輸出，其中該第二差分驅動器包括第三負電壓驅動電路與第四負電壓驅動電路，分別提供該第三負輸出端及第四負輸出端。 The earphone driver as described in claim item 7, further comprising: a second differential driver, including a second positive output terminal, a third negative output terminal and a fourth negative output terminal, the second positive output terminal is connected to the second terminal and the second switch unit, arranged on the feedback path of the third negative output terminal and the fourth negative output terminal, is planned to enable the feedback of the third negative output terminal and enable the third negative output terminal in the first operation state. The closed-loop output of the negative output terminal is output to the third terminal, and the feedback of the fourth negative output terminal is disabled and the open-loop output of the fourth negative output terminal is disabled, and the fourth negative output terminal is enabled in the second operating state. Feedback at the negative output terminal and make the closed-loop output of the fourth negative output terminal to the fourth terminal, and disable the feedback of the third negative output terminal and disable the open-loop output of the third negative output terminal, wherein the second The differential driver includes a third negative voltage driving circuit and a fourth negative voltage driving circuit, respectively providing the third negative output terminal and the fourth negative output terminal.

如請求項8所述的耳機驅動器，其中該第二開關單元依照該第一操作狀態或該第二操作狀態啟動該第三負電壓驅動電路與該第四負電壓驅動電路的其一。 The headphone driver as claimed in claim 8, wherein the second switch unit activates one of the third negative voltage driving circuit and the fourth negative voltage driving circuit according to the first operation state or the second operation state.

如請求項9所述的耳機驅動器，其中該第一差分驅動器與該第二差分驅動器的每一個更包括開關電路，設置在該第一正輸出端與該第二正輸出端的回授路徑上，用以在待機狀態下斷開。 The headphone driver as claimed in item 9, wherein each of the first differential driver and the second differential driver further includes a switch circuit disposed on the feedback path of the first positive output terminal and the second positive output terminal, Used to disconnect in standby mode.

如請求項10所述的耳機驅動器，其中該第一正輸出端與該第二正輸出端分別驅動該耳機裝置的第一喇叭與第二喇叭，其中該第三端與第四端之設置一麥克風，其中該第一、第二、第三、第四負輸出端通過該第一開關單元與該第二開關單元提供該麥克風的負極電壓。 The earphone driver as described in claim 10, wherein the first positive output terminal and the second positive output terminal respectively drive the first speaker and the second speaker of the earphone device, wherein the third terminal and the fourth terminal are provided with a A microphone, wherein the first, second, third and fourth negative output terminals provide the negative voltage of the microphone through the first switch unit and the second switch unit.

如請求項10所述的耳機驅動器，其中該第一開關單元與該第二開關單元分別包含多個N型電晶體與多個P型電晶體，其中該多個N型電晶體是包含深N形井區的基底。 The headphone driver according to claim 10, wherein the first switch unit and the second switch unit respectively comprise a plurality of N-type transistors and a plurality of P-type transistors, wherein the plurality of N-type transistors comprise deep N The base of the shaped well area.

一種耳機驅動方法，用於驅動耳機裝置，其中該耳機裝置有固定位置的第一、第二、第三及第四端點，該耳機驅動方法包括：使用第一差分驅動器驅動該耳機裝置的第一聲道及一麥克風，該第一差分驅動器包含第一正輸出端，第一負輸出端及第二負輸出端，該第一正輸出端接到該第一端點；以及使用第一開關單元，設置在該第一負輸出端及該第二負輸出端的回授路徑上，規劃成在第一操作狀態時切換成使該第一負輸出端連接到該第三端點，而該第二負輸出端斷開，以及在第二操作狀態時切換成使該第二負輸出端連接到該第四端點，而該第一負輸出端斷開，其中該第一差分驅動器包括第一負電壓驅動電路及第二負電壓驅動電路，分別提供該第一負輸出端及第二負輸出端。 A headphone driving method for driving a headphone device, wherein the headphone device has first, second, third and fourth terminals at fixed positions, the headphone driving method includes: using a first differential driver to drive the first end of the headphone device One channel and a microphone, the first differential driver includes a first positive output terminal, a first negative output terminal and a second negative output terminal, the first positive output terminal is connected to the first terminal; and a first switch is used unit, set at the first negative output terminal and the second negative output On the feedback path of the terminal, it is planned to switch to connect the first negative output terminal to the third terminal in the first operating state, and disconnect the second negative output terminal, and switch to The second negative output terminal is connected to the fourth terminal, and the first negative output terminal is disconnected, wherein the first differential driver includes a first negative voltage drive circuit and a second negative voltage drive circuit, respectively providing the first A negative output terminal and a second negative output terminal.

如請求項13所述的耳機驅動方法，其中該第一開關單元依照該第一操作狀態或該第二操作狀態啟動該第一負電壓驅動電路與該第二負電壓驅動電路的其一。 The headphone driving method according to claim 13, wherein the first switch unit activates one of the first negative voltage driving circuit and the second negative voltage driving circuit according to the first operating state or the second operating state.

如請求項14所述的耳機驅動方法，還包括：使用第二差分驅動器，驅動該耳機裝置的第二聲道及該麥克風，該第二差分驅動器包含第二正輸出端，第三負輸出端及第四負輸出端，該第二正輸出端接到該第二端點；以及使用第二開關單元，設置在該第三負輸出端及該第四負輸出端的回授路徑上，規劃成在該第一操作狀態時切換成使該第三負輸出端連接到該第三端點，而該第四負輸出端斷開，以及在該第二操作狀態時切換成使該第四負輸出端連接到該第四端點，而該第三負輸出端斷開，其中該第二差分驅動器包括第三負電壓驅動電路與第四負電壓驅動電路，分別提供該第三負輸出端及第四負輸出端。 The headphone driving method as described in claim 14, further comprising: using a second differential driver to drive the second sound channel and the microphone of the earphone device, the second differential driver includes a second positive output terminal and a third negative output terminal and the fourth negative output terminal, the second positive output terminal is connected to the second terminal; and a second switch unit is used, which is arranged on the feedback path of the third negative output terminal and the fourth negative output terminal, and is planned as In the first operating state, it is switched to make the third negative output terminal connected to the third terminal, while the fourth negative output terminal is disconnected, and in the second operating state, it is switched to make the fourth negative output terminal is connected to the fourth terminal, and the third negative output terminal is disconnected, wherein the second differential driver includes a third negative voltage drive circuit and a fourth negative voltage drive circuit, which provide the third negative output terminal and the first negative voltage drive circuit respectively. Four negative output terminals.

如請求項15所述的耳機驅動方法，其中該第二開關單元依照該第一操作狀態或該第二操作狀態啟動該第三負電壓驅動電路與該第四負電壓驅動電路的其一。 The headphone driving method according to claim 15, wherein the second switch unit activates one of the third negative voltage driving circuit and the fourth negative voltage driving circuit according to the first operation state or the second operation state.

如請求項16所述的耳機驅動方法，其中該第一差分驅動器與該第二差分驅動器的每一個更包括開關電路，設置在該第一正輸出端與該第二正輸出端的回授路徑上，用以在待機狀態下斷開。 The headphone driving method as claimed in claim 16, wherein each of the first differential driver and the second differential driver further includes a switch circuit disposed on the feedback path between the first positive output terminal and the second positive output terminal , to disconnect in standby mode.

如請求項17所述的耳機驅動方法，其中該第一正輸出端與該第二正輸出端分別驅動該耳機裝置的第一喇叭與第二喇叭，其中該第三端與第四端之設置一麥克風，其中該第一、第二、第三、第四負輸出端通過該第一開關單元與該第二開關單元提供該麥克風的負極電壓。 The headphone driving method according to claim 17, wherein the first positive output terminal and the second positive output terminal respectively drive the first speaker and the second speaker of the earphone device, wherein the setting of the third terminal and the fourth terminal A microphone, wherein the first, second, third and fourth negative output terminals provide the negative voltage of the microphone through the first switch unit and the second switch unit.

如請求項18所述的耳機驅動方法，其中所使用的該第一開關單元與該第二開關單元分別包含多個N型電晶體與多個P型電晶體，其中該多個N型電晶體是包含深N形井區的基底。 The headphone driving method according to claim 18, wherein the first switch unit and the second switch unit used respectively include a plurality of N-type transistors and a plurality of P-type transistors, wherein the plurality of N-type transistors is the substrate containing the deep N-well region.

如請求項13所述的耳機驅動方法，其中該第一操作狀態與該第二操作狀態的判斷包括：施加一電壓差在該第三端點與該第四端點之間；以及偵測在該第一端點與該第二端點其一的第一電壓以及在第三端點的第二電壓，其中該第一電壓與該第二電壓實質相同，則是該第一操作狀態，其中該第一電壓與該第二電壓實質不同，則是該第二操作狀態。 The earphone driving method as described in claim 13, wherein the judgment of the first operating state and the second operating state includes: applying a voltage difference between the third terminal and the fourth terminal; and detecting a first voltage at one of the first terminal and the second terminal and a second voltage at a third terminal, wherein the first voltage and the second voltage are substantially the same, being the first operating state, Where the first voltage is substantially different from the second voltage, it is the second operating state.