TW201618405A

TW201618405A - Power supply circuit

Info

Publication number: TW201618405A
Application number: TW103131505A
Authority: TW
Inventors: 彭章龍; 陳俊生
Original assignee: 鴻海精密工業股份有限公司
Priority date: 2014-09-12
Filing date: 2014-09-12
Publication date: 2016-05-16

Abstract

A power supply circuit includes an input circuit and a switch circuit. The switch circuit includes a first switch and a second switch. An input terminal of the input circuit is configured to receive a first DC voltage. A first terminal of the first switch is configured to receive a control signal. A second terminal of the first switch is grounded. A third terminal of the first switch is electrically coupled to a first terminal of the second switch. A second terminal of the second switch is configured to output a second DC voltage. A third terminal of the second switch is electrically coupled to an output terminal of the input circuit. When the second DC voltage is overvoltage, the first switch receives the control signal and turns off, the second switch turns off, the second terminal and the third terminal of the second switch are cut off, and the second terminal of the second switch can not output the second DC voltage.

Description

供電保護電路Power supply protection circuit

本發明涉及一種供電保護電路，特別涉及一種可防止過大電壓燒壞電路元件之供電保護電路。The invention relates to a power supply protection circuit, in particular to a power supply protection circuit capable of preventing an excessive voltage from burning out circuit components.

於現今之臺式電腦中通常採用一供電電路將220V之市電電壓轉換為多個不同之直流電壓對電腦主機板進行供電，習知之供電電路不具有過壓保護功能，當220V之市電電壓之輸入電壓不穩定時會導致輸出之直流電壓過大，進而導致電腦主機板上之電路元件被損壞。In today's desktop computers, a power supply circuit is usually used to convert the 220V mains voltage into a plurality of different DC voltages to supply power to the computer motherboard. The conventional power supply circuit does not have an overvoltage protection function. When the 220V mains voltage is input, When the voltage is unstable, the DC voltage of the output is too large, which may cause damage to circuit components on the computer motherboard.

有鑑於此，有必要提供一種可防止過大電壓燒壞電路元件之供電保護電路。In view of the above, it is necessary to provide a power supply protection circuit that prevents excessive voltage from burning out circuit components.

一種供電保護電路，包括一輸入電路和一開關電路，所述輸入電路之輸入端接收一第一直流電壓，所述輸入電路之輸出端電性連接所述開關電路，所述開關電路包括一第一開關和一第二開關，所述第一開關之第一端接收一控制訊號，所述第一開關之第二端接地，所述第一開關之第三端電性連接所述第二開關之第一端，所述第二開關之第二端輸出一第二直流電壓，所述第二開關之第三端電性連接所述輸入電路之輸出端，當所述第二直流電壓過壓時，所述第一開關接收所述控制訊號並截止，所述第二開關截止，所述第二開關之第二端和之第三端被斷開，使得所述第二開關之第二端無法輸出所述第二直流電壓。A power supply protection circuit includes an input circuit and a switch circuit, wherein an input end of the input circuit receives a first DC voltage, and an output end of the input circuit is electrically connected to the switch circuit, and the switch circuit includes a first a switch and a second switch, the first end of the first switch receives a control signal, the second end of the first switch is grounded, and the third end of the first switch is electrically connected to the second switch The second end of the second switch outputs a second DC voltage, and the third end of the second switch is electrically connected to the output end of the input circuit, when the second DC voltage is overvoltage The first switch receives the control signal and turns off, the second switch is turned off, and the second end and the third end of the second switch are disconnected, so that the second end of the second switch The second DC voltage cannot be output.

相較於先前技術，本發明提供的供電保護電路當所述第二直流電壓過壓時，所述第一開關接收所述控制訊號並截止，所述第二開關截止，所述第二開關之第二端和之第三端被斷開，使得所述第二開關之第二端無法輸出所述第二直流電壓，進而避免過大之第二直流電壓燒壞電路元件。Compared with the prior art, the power supply protection circuit provided by the present invention, when the second DC voltage is overvoltage, the first switch receives the control signal and is turned off, the second switch is turned off, and the second switch is The second end and the third end are disconnected such that the second end of the second switch is unable to output the second DC voltage, thereby preventing the excessive DC voltage from burning out the circuit component.

圖1為本發明供電保護電路之一較佳實施方式之框圖。1 is a block diagram of a preferred embodiment of a power protection circuit of the present invention.

圖2為圖1中供電保護電路之電路圖。2 is a circuit diagram of the power supply protection circuit of FIG. 1.

請參閱圖1，於本發明之一較佳實施方式中，一供電保護電路包括一輸入電路100、一開關電路200及一去耦電路300。Referring to FIG. 1 , in a preferred embodiment of the present invention, a power supply protection circuit includes an input circuit 100 , a switch circuit 200 , and a decoupling circuit 300 .

所述輸入電路100包括一保險絲F和一第一電容C1。所述保險絲F之一端作為所述輸入電路100之輸入端接收一+5V之第一直流電壓，所述保險絲F之一端經由所述第一電容C1接地。所述保險絲F之另一端作為所述輸入電路100之輸出端電性連接所述開關電路200。其中，所述保險絲F之額定電流為1.25A，所述保險絲F之額定電壓為250V。The input circuit 100 includes a fuse F and a first capacitor C1. One end of the fuse F receives a first DC voltage of +5V as an input end of the input circuit 100, and one end of the fuse F is grounded via the first capacitor C1. The other end of the fuse F is electrically connected to the switch circuit 200 as an output end of the input circuit 100. Wherein, the rated current of the fuse F is 1.25A, and the rated voltage of the fuse F is 250V.

所述開關電路200包括一第一場效應電晶體Q1、一第二場效應電晶體Q2及一第一電阻R1。所述第一場效應電晶體Q1之閘極接收一HDMI晶片400輸出之控制訊號。所述第一場效應電晶體Q1之源極接地。所述第一場效應電晶體Q1之汲極經由所述第一電阻R1電性連接所述第二場效應電晶體Q2之閘極。所述第二場效應電晶體Q2之汲極電性連接所述保險絲F之另一端。所述第二場效應電晶體Q2之源極輸出一第二直流電壓給一HDMI介面500。其中，所述第一場效應電晶體Q1為N溝道場效應電晶體，所述第二場效應電晶體Q2為P溝道場效應電晶體。所述第二直流電壓為一+5V之顯示資料通道電壓。The switch circuit 200 includes a first field effect transistor Q1, a second field effect transistor Q2, and a first resistor R1. The gate of the first field effect transistor Q1 receives a control signal output by the HDMI chip 400. The source of the first field effect transistor Q1 is grounded. The drain of the first field effect transistor Q1 is electrically connected to the gate of the second field effect transistor Q2 via the first resistor R1. The drain of the second field effect transistor Q2 is electrically connected to the other end of the fuse F. The source of the second field effect transistor Q2 outputs a second DC voltage to an HDMI interface 500. The first field effect transistor Q1 is an N-channel field effect transistor, and the second field effect transistor Q2 is a P channel field effect transistor. The second DC voltage is a display data channel voltage of +5V.

所述去耦電路300包括一第二電阻R2和一第二電容C2。所述第二電阻R2和所述第二電容C2之一端分別電性連接所述第二場效應電晶體Q2之閘極。所述第二電阻R2和所述第二電容C2之另一端分別電性連接所述第二場效應電晶體Q2之源極。The decoupling circuit 300 includes a second resistor R2 and a second capacitor C2. One ends of the second resistor R2 and the second capacitor C2 are electrically connected to the gates of the second field effect transistor Q2, respectively. The other ends of the second resistor R2 and the second capacitor C2 are electrically connected to the sources of the second field effect transistor Q2, respectively.

工作時，所述HDMI晶片400偵測所述第二直流電壓之狀態以輸出所述控制訊號。當所述第二直流電壓遠大於+5V時，所述HDMI晶片400輸出一低電位之控制訊號；所述第一場效應電晶體Q1之閘極接收所述低電位之控制訊號，所述第一場效應電晶體Q1截止；所述第二場效應電晶體Q2之閘極為高電位，所述第二場效應電晶體Q2截止；此時所述第二場效應電晶體Q2之源極和汲極被斷開，所述第二場效應電晶體Q2之源極無法輸出所述第二直流電壓給所述HDMI介面500，進而避免過大之第二直流電壓燒壞所述HDMI介面500而起到保護作用。In operation, the HDMI chip 400 detects the state of the second DC voltage to output the control signal. When the second DC voltage is much greater than +5V, the HDMI chip 400 outputs a low potential control signal; the gate of the first field effect transistor Q1 receives the low potential control signal, the first One effect transistor Q1 is turned off; the gate of the second field effect transistor Q2 is extremely high, and the second field effect transistor Q2 is turned off; at this time, the source of the second field effect transistor Q2 is 汲The pole of the second field effect transistor Q2 is unable to output the second DC voltage to the HDMI interface 500, thereby preventing the excessive DC voltage from burning out the HDMI interface 500. Protective effects.

當所述第二直流電壓為+5V時，所述HDMI晶片400輸出一高電位之控制訊號；所述第一場效應電晶體Q1之閘極接收所述高電位之控制訊號，所述第一場效應電晶體Q1導通；所述第二場效應電晶體Q2之閘極為低電位，所述第二場效應電晶體Q2導通；此時所述第二場效應電晶體Q2之源極和汲極被電性連通，所述第二場效應電晶體Q2之源極輸出所述第二直流電壓給所述HDMI介面500，進而為所述HDMI介面500提供工作電壓而保證其供電。於供電過程中，所述去耦電路300用以去除所述第二直流電壓上之雜訊電壓，避免了雜訊電壓對所述HDMI介面500之影響。When the second DC voltage is +5V, the HDMI chip 400 outputs a high potential control signal; the gate of the first field effect transistor Q1 receives the high potential control signal, the first The field effect transistor Q1 is turned on; the gate of the second field effect transistor Q2 is extremely low, and the second field effect transistor Q2 is turned on; at this time, the source and the drain of the second field effect transistor Q2 The source of the second field effect transistor Q2 outputs the second DC voltage to the HDMI interface 500, thereby providing an operating voltage to the HDMI interface 500 to ensure power supply. During the power supply process, the decoupling circuit 300 is configured to remove the noise voltage on the second DC voltage, thereby avoiding the influence of the noise voltage on the HDMI interface 500.

綜上所述，本發明確已符合發明專利之要件，遂依法提出專利申請。惟，以上所述者僅為本發明之較佳實施方式，自不能以此限制本案之申請專利範圍。舉凡熟悉本案技藝之人士爰依本發明之精神所作之等效修飾或變化，皆應涵蓋於以下申請專利範圍內。In summary, the present invention has indeed met the requirements of the invention patent, and has filed a patent application according to law. However, the above description is only a preferred embodiment of the present invention, and it is not possible to limit the scope of the patent application of the present invention. Equivalent modifications or variations made by persons skilled in the art in light of the spirit of the invention are intended to be included within the scope of the following claims.

100‧‧‧輸入電路100‧‧‧Input circuit

200‧‧‧開關電路200‧‧‧Switch circuit

300‧‧‧去耦電路300‧‧‧Decoupling circuit

400‧‧‧HDMI晶片400‧‧‧HDMI chip

500‧‧‧HDMI介面500‧‧‧HDMI interface

F‧‧‧保險絲F‧‧‧Fuse

C1‧‧‧第一電容C1‧‧‧first capacitor

Q1‧‧‧第一場效應電晶體Q1‧‧‧First field effect transistor

Q2‧‧‧第二場效應電晶體Q2‧‧‧Second field effect transistor

R1‧‧‧第一電阻R1‧‧‧first resistance

R2‧‧‧第二電阻R2‧‧‧second resistance

C2‧‧‧第二電容C2‧‧‧second capacitor

無no

100‧‧‧輸入電路 100‧‧‧Input circuit

200‧‧‧開關電路 200‧‧‧Switch circuit

300‧‧‧去耦電路 300‧‧‧Decoupling circuit

400‧‧‧HDMI晶片 400‧‧‧HDMI chip

500‧‧‧HDMI介面 500‧‧‧HDMI interface

Claims

如請求項1所述的供電保護電路，其中：當所述第二直流電壓正常時，所述第一開關接收所述控制訊號並導通，所述第二開關導通，所述第二開關之第二端和之第三端被電性連通，所述第二開關之第二端輸出所述第二直流電壓。The power protection circuit of claim 1, wherein: when the second DC voltage is normal, the first switch receives the control signal and is turned on, the second switch is turned on, and the second switch is The second end and the third end are electrically connected, and the second end of the second switch outputs the second DC voltage.

如請求項1所述的供電保護電路，其中：所述第一開關和所述第二開關為場效應電晶體，所述第一端、所述第二端及所述第三端分別為閘極、源極及汲極。The power protection circuit of claim 1, wherein: the first switch and the second switch are field effect transistors, and the first end, the second end, and the third end are respectively gates Pole, source and bungee.

如請求項1所述的供電保護電路，其中：所述第一開關為N溝道場效應電晶體，所述第二開關為P溝道場效應電晶體。The power protection circuit of claim 1, wherein: the first switch is an N-channel field effect transistor, and the second switch is a P-channel field effect transistor.

如請求項1所述的供電保護電路，其中：所述第一直流電壓之大小為+5V，所述第二直流電壓為一+5V之顯示資料通道電壓。The power protection circuit of claim 1, wherein: the first DC voltage is +5V, and the second DC voltage is a +5V display data channel voltage.

如請求項1所述的供電保護電路，其中：所述輸入電路包括一保險絲和一第一電容，所述保險絲之一端作為所述輸入電路之輸入端接收所述第一直流電壓，所述保險絲之一端經由所述第一電容接地，所述保險絲之另一端作為所述輸入電路之輸出端電性連接所述第二開關之第三端。The power supply protection circuit of claim 1, wherein: the input circuit comprises a fuse and a first capacitor, and one end of the fuse receives the first DC voltage as an input end of the input circuit, the fuse One end is grounded via the first capacitor, and the other end of the fuse is electrically connected to the third end of the second switch as an output end of the input circuit.

如請求項1所述的供電保護電路，其中：所述開關電路還包括一第一電阻，所述第一開關之第三端經由所述第一電阻電性連接所述第二開關之第一端。The power supply protection circuit of claim 1, wherein the switch circuit further includes a first resistor, and the third end of the first switch is electrically connected to the first switch via the first resistor end.

如請求項1所述的供電保護電路，其中：所述供電保護電路還包括一去耦電路，所述去耦電路包括一第二電阻和一第二電容，所述第二電阻和所述第二電容之一端分別電性連接所述第二開關之第一端，所述第二電阻之另一端分別電性連接所述第二開關之第二端。The power protection circuit of claim 1, wherein: the power protection circuit further includes a decoupling circuit, the decoupling circuit includes a second resistor and a second capacitor, the second resistor and the One end of the second capacitor is electrically connected to the first end of the second switch, and the other end of the second resistor is electrically connected to the second end of the second switch.

如請求項1所述的供電保護電路，其中：所述第一開關之第一端電性連接一HDMI晶片以接收所述控制訊號。The power protection circuit of claim 1, wherein the first end of the first switch is electrically connected to an HDMI chip to receive the control signal.

如請求項1所述的供電保護電路，其中：所述第二開關之第二端電性連接一HDMI介面從而輸出所述第二直流電壓給所述HDMI介面。
The power protection circuit of claim 1, wherein the second end of the second switch is electrically connected to an HDMI interface to output the second DC voltage to the HDMI interface.