1378641 HS-2008-0056-TW 30502twf.doc/n 六、發明說明： 【發明所屬之技術領域】 本發明是有關於一種信號轉換器，且特別是有關於一 種降低電磁干擾的信號轉換器。 【先前技術】 近年來，由於印刷電路板（Printed circuit board， PCB)不斷進步，使得電子產品的應用日益廣泛且需求曰 益增加’各種電子產品的電路設計也越來越複雜。為了符 合尚性能及高反應度的要求，數位資料傳輸速度越來越 快’而電晶體對電晶體邏輯(Transist〇r_Transistor Logic， TTL)信號傳輸的頻率極限僅約為5〇MHz。因此，倘若TTL 仏號要達到全擺幅(full swing)的上升時間(rising time)過長 時，TTL信號將無法應用在高速傳輸的方式。針對此種情 況，TTL信號在傳送的過程中，通常會透過一信號轉換器 轉換成差動小信號的方式去傳送，其中差動小信號所需的 上升時間較短，因此可以滿足高速傳輸的需求。 雖然差動小信號可以減少轉態的時間以達到更快的 操作頻率，但在傳送的過程中往往都會遇到電磁干擾 (Electromagnetic Interference，EMI)的問題。電磁干擾主要 可分為輕射性(Radiated)與傳導性(Conducted)電磁干擾。輻 射性電磁干擾是直接經由開放空間傳遞，不須要經由任何 ，輸介質，故一般僅能以遮蔽(Shielding)、接地(Gr〇unding) 等方式來解決。而傳導性電磁干擾是經由電源導線來傳遞 雜訊。因此，連接在同一個系統的電子裝置所產生的電磁 ^S-2〇〇8-〇〇56-TW 30502twf.doc/n :擾會經的源_彼此相互干擾，造成在傳輸 2號判讀將’使得產品輪“能不正常岐^因^ 【發明内容】 的電供—齡輪器，毫錢傳輸時發生 本發明提出-種信號轉換器，包括第—電流源 電流源、第-切換單元、第二城單元、第—電容 ^二電容單元。其中’第-電流源用以提供參考電流。第 p刀換單元用以依據絲輸人錢將參考電 切換單元的第二端或第三端。差動給 —弟 單元的第二端與第三端取出，即由第切換 ^ t ^ 丨田弟—力而上的輸出信號及 、二步而上的輪出信號取出差動輸出信號。第二切換單元用 以依據差動輸入信號而將流經負載的參考電流導向至第二 切換單it的第-端。第二電流源用㈣集參考電流。第: 電”依據：換信號來調整第-電容單元所對應的 電各值。第二電容單TL用以依據切換信號來調整第二電容 單元所對應的電容值。 ★在本發明之一實施例中，上述之第一電容單元包括多 個第一開關及多個第一電容。其中，此些第一開關的第一 端，接至第-切換單元的第—端’並分驗據切換信號而 決定其導通狀態。另外，此些第一電容分別與此些第一開 關一對一對應，其中此些第一電容的第一端各自耦接至對 應之第一開關的第二端，且此些第—電容的第二端耦接至 1378641 HS-2〇〇8-〇〇56.xw 30502twf.doc/n 接地電壓。 在本發明之-實施例中，上述之第二電容單元包 個第二開關及多個第二電容。其中，此些 端耦接至第二切換單元的第一端，並、 ^疋八導通14。另外’此些第二電容分別與此些第二開 =一對-對應，其中此些第二電容的第―端各自输至對 開關的第二端，且此些第二電容的第二端搞接至 接1地電堡。 在本發明之-實施例中，上述之第一電容單元盘第二 電容單元更參照絲輸人錢的鱗來控制_信號，: 致使第:電容單讀第二電容單元所對應之電容值社小 相關於差動輸入信號的頻率。 —基於上述’本發明可藉由設定第—電容單元及第 容單^的電容值’來減低開關切換所造成的電磁干擾 濾除第一電流源與第二電流源所產生的雜訊。 —為讓本剌之上祕徵和優點能更鴨雜，下文 舉實施例，並配合所附圖式作詳細說明如下。 、 【實施方式】 習知的信號轉換器，雖可將擺幅(swing)較大的資料传 號轉為差動:1、錢，以符合高速傳送數位·的需求。； A號轉換ϋ操作簡率越快時，電磁干擾也越嚴重，如 此將使得產品輪出功衫正f，或是壽命因此減短。 有鑒於此，本發明的實施例提供一種信號轉換器， 以減低信號轉換器在高速操作時所產生㈣磁干擾，以避 HS-2008-0056-TW 30502twf.doc/n. 免在傳輸信號過程中信號判讀錯誤’使得產品輪出功能不 正常。下面將參考附圖詳細闡述本發明的實施例，附圖舉 例說明了本發明的示範實施例’其中相同標號指示同樣或 相似的元件。 圆1疋依照本發明一實施例之信號轉換器的電路圖。 請參照圖1 ’本實施例所提供的信號轉換器10()主要包括 一第一電流源A1、一第二電流源A2、一第一切換單元 102、一第二切換單元1〇4、一第一電容單元1〇6以及一第 二電容單元1〇8。其中，圖1更繪示出信號轉換器100名 實際應用上所外接的負載110。在此，負载110例如是信 =換器1GG的下級電路(例如信號接收器）或是信號傳^ 為了·方便起見’圖1更繪 二、 的等效電路，且此等效電路包括電阻R〇、電 容CP1及電容CP2。 私氏电 具有，電源電壓VS。第—切換單元102 第一端TM 1至第三端TM23。第一切換單元102的 的第二端M °第—切換單元搬 端。第二域料H她嫌卜接至貞載no的兩 接至第—切換 t = ΤΜ42與第三端態3分_ 第二電流源Α2 _在^二端™22與第三端Τ廳。 與接地電壓GND 1弟〜切換單元刚的第一端™41 第一切換單元1〇2的電容單元1〇6輕接在 弟、TM21與接地電壓GND之間。 1378641 HS-2008-0056-TW 30502twf.doc/n 第二電容單元108與第二電流源A2相互並聯。 其中，第一電流源A1用以提供一參考電流II。第一 切換單元102用以依據一差動輸入信號將參考電流η 導向至其第二端ΤΜ22或第三端ΤΜ23。另一方面，第二 切換單元104會依據差動輸入信號〇1而將流經負載11〇 的參考電流II導向至第二切換單元104的第一端TM41。 第二電流源A2則用以匯集參考電流η。 如此一來，隨著第一切換單元102與第二切換單元1〇4 對參考電流II之流向的切換’參考電流η將流經負載11〇 並在負載110的兩端形成一差動輸出信號D2，也就是壓降 在第一切換單元102之第二端了“^上的輸出信號D21以 及其第三端TM23上的輸出信號D22。在此，差動輸出信 旒D2的振幅小於差動輪入信號〇1的振幅，故經由信號轉 換器100轉換的差動輸入信號，將滿足高速傳輸的需 求。 另一方面，第一電容單元1〇6用以依據切換信號si 來調整第一電容單元106所對應的電容值。第二電容單元 用以依據切換信號S1來調整第二電容單元1〇8所對應 的電容值。其中’第一電容單元1〇6與第二電容單元1〇8 更參照差動輸入信號D1的頻率來控制切換信號幻，使第 —電容單元106與第二電容單元1〇8所對應之電容值的大 小相關於差動輸入信號D1的頻率。藉此，第一電容單元 與第二電容單元1〇8將可有效地濾除’第—切換 1〇2與第二切換單元刚在切換參考電流^之瞬間所形成 1378641 HS-2008-0056-TW 30502twf.doc/n 的突波。 在本發明的另一實施例中，圖！中的差動輸入信號 D1包括兩個互不重疊的輸入信號，而第—切換單元1〇2 一弟一切換單元104各可包括兩個開關。舉例來說，圖2 是依照本發明另一實施例之信號轉換器的電路圖，圖3是 $照本發明-實施例之差動輸人信號與差動輸出信號的示 思'圖。5月參照圖2與圖3，本實施例中的差動輸入信號D1 • 包括互不重疊的第一輸入信號Dll與第二輸入信號〇12。 其中，信號在高準位時為致能，在低準位時為失能。因此， ^第一輸入信號D11為致能之期間第二輸入信號D12為失 能，當第二輸入信號D12為致能之期間第一輸入信號^^” 為失能，且兩輸入信號不同時為致能。 —另外，第一切換單元1〇2包括一第一開關SW1以及 :第二開關SW2。其中，第一開關SW1之第一端耦接至 切換單元1〇2的第一端TM21，第一開關SW1的第二 端，接至第一切換單元102的第二端TM22。第二開關SW2 _ W第-端_接至第一切換單元lG2的第一端TM2l，第二 開關SW2的第二端耦接至第一切換.單元1〇2的第三端 TM23 〇 第二切換單元1〇4則包括一第三開關SW3以及—第 四開關SW4。其中，第三開關SW3的第一端輕接至第二 切換單兀104的第二端TM42，第三開關SW3的第二端耦 ，至第二切換單元104的第一端TM41。第四開關SW4的 第一端耦接至第二切換單元1〇4的第三端TM43，第四開 9 1378641 HS-2008-0056-TW 30502tw-f.doc/n 關SW4的第二端箱接至第二切換單元1〇4的第一端 TM41。此外，第一開關SW1至第四開關SW4可以分別由 一個至多個電晶體所構成。 針對第一切換單元102與第二切換單元1〇4的細部操 作來看。其中，第一開關SW1與第四開關SW4依據第一 輸入信號D11來切換其本身的導通狀態，而第二開關SW2 與第二開關SW3依據第二輸入信號D12來切換其本身的 導通狀態。 、 在此’當第一輸入信號Dll為致能之期間，第一開關 SW1及第四開關SW4為導通，而第二開關及第二門 關SW3為斷開。因此，第一電流源A1所提供的來考電、'辛 II將由導通的第一開關SW1的第一端流入，並流經負g 110而由導通的第四開關SW4的第二端流出，進而^第二 電流源A2所匯集。此時，依據參考電流只的流向可知， 第一切換單元102的第二端TM22將可產生具有高準^ 輸出信號D21，且第一切換單元102的第三端丁1^23將可 產生具有低準位的輸出信號D22。 相對地，當第二輸入信號為致能之期間，第二 關SW2及第三開關SW3為導通’而第一開關撕及^ 開關SW4為斷開。因此，第一電流源A1所提供的參= 流II將由導通的第二開關SW2的第一端流入並^狖電 載H0而由導通的第三開關SW3的第二端流出，進二= 二電流源A 2所匯集。此時’依據參考電流〗丨的产弟 第一切換單元1〇2的第二端TM22將可產生具有•低^位的 HS-2008-0056-TW 30502twf.doc/n ^信號^21，且第—切換單元102的第三端TM23將可 產生具有尚準位的輪出信號。 切換值隨著第一開關SW1至第四開關sw4的 交替<參考電流11的流向也將不斷地反覆 ^替。猎此’負載11G的兩端將 ==信號D22,也就是差動輸出信號二中 卩為參考電流n之電流值與負載 之門mm…積’也就是輪出信號d21與輸出信號d22 外？圖3所示，差動輸出信謂的 二-田μ -的振幅L1，且在第一電容 電各早凡108的作用下，差動輸出信號D2 二:ί的突波將可有效地被濾除。 祕相=:Ϊ ’當第—開關SW1至第四開關SW4的 :換=寺，第-開關_之第二端上的電壓，以及 Ϊ;= 二二曹端上的_，其瞬間_^^^ Φ厫重。為了減低電磁干擾，本實施例可 單元1〇6與第二電容單元⑽所等效的 4 開關切換時轉上衝及下衝所造成的電壓 ί ί訊心慮除第一電流源A1與第二電流源Α2所產生 、畜、_電容單元106與第二電容單元108可用來 二Γίί^皮2和釋放電荷以缓和輸出信號 以較高頻率切開關_至第四開關sw4 、才弟電各單元1〇6與第二電容單元1〇8 1 J / oun· HS-2008-0056-TW 30502twf.d〇c/n1378641 HS-2008-0056-TW 30502twf.doc/n VI. Description of the Invention: [Technical Field] The present invention relates to a signal converter, and more particularly to a signal converter for reducing electromagnetic interference. [Prior Art] In recent years, due to the continuous advancement of printed circuit boards (PCBs), the application of electronic products has become more widespread and the demand has increased. The circuit design of various electronic products has become more and more complicated. In order to meet the requirements of high performance and high responsiveness, digital data transmission speed is getting faster and faster, and the frequency limit of transistor to Transist〇r_Transistor Logic (TTL) signal transmission is only about 5〇MHz. Therefore, if the TTL nickname is too long for the full swing, the TTL signal will not be applied to the high-speed transmission. In this case, during the transmission process, the TTL signal is usually transmitted by means of a signal converter to be converted into a differential small signal, wherein the differential small signal requires a shorter rise time, thereby satisfying the high-speed transmission. demand. Although the differential small signal can reduce the transition time to achieve a faster operating frequency, it often encounters electromagnetic interference (EMI) during transmission. Electromagnetic interference can be mainly divided into Radiated and Conducted electromagnetic interference. Radiated electromagnetic interference is transmitted directly through the open space. It does not need to be transmitted through any medium. Therefore, it can only be solved by Shielding or Grunding. Conductive electromagnetic interference is transmitted through the power conductors. Therefore, the electromagnetics generated by the electronic devices connected to the same system ^S-2〇〇8-〇〇56-TW 30502twf.doc/n: the source of the disturbances interfere with each other, causing the interpretation of the transmission No. 2 [Make the product wheel "can not be normal" ^ [Invention] The electric supply-age wheel device, when the money is transmitted, the present invention proposes a signal converter, including the first current source current source, the first-switching unit , the second city unit, the first capacitor, the second capacitor unit, wherein the 'first current source is used to provide a reference current. The first p-tool replacement unit is used to refer to the second end or the third of the electric switching unit according to the wire input money. The second end and the third end of the differential unit are taken out, that is, the output signal of the switch and the output signal of the second step are taken out, and the differential output signal is taken out. The second switching unit is configured to direct the reference current flowing through the load to the first end of the second switching unit it according to the differential input signal. The second current source uses (4) the set reference current. To adjust the electrical values corresponding to the first capacitor unit. The second capacitor single TL is used to adjust the capacitance value corresponding to the second capacitor unit according to the switching signal. In an embodiment of the invention, the first capacitor unit includes a plurality of first switches and a plurality of first capacitors. The first end of the first switch is connected to the first end of the first switching unit and determines the conduction state according to the switching signal. In addition, the first capacitors are respectively in one-to-one correspondence with the first switches, wherein the first ends of the first capacitors are respectively coupled to the second ends of the corresponding first switches, and the first capacitors The second end is coupled to 1789641 HS-2〇〇8-〇〇56.xw 30502twf.doc/n ground voltage. In an embodiment of the invention, the second capacitor unit includes a second switch and a plurality of second capacitors. The terminals are coupled to the first end of the second switching unit, and are turned on. In addition, the second capacitors are respectively corresponding to the second open=pairs, wherein the first ends of the second capacitors are respectively input to the second end of the pair of switches, and the second ends of the second capacitors Get connected to the 1st electric castle. In the embodiment of the present invention, the second capacitive unit of the first capacitive unit disk further controls the _ signal by referring to the scale of the input of the human money: causing the capacitor to be read by the second capacitor unit. Small relative to the frequency of the differential input signal. - Based on the above, the present invention can reduce the electromagnetic interference caused by the switching of the switch by setting the capacitance value of the first capacitor unit and the second capacitor unit to filter out the noise generated by the first current source and the second current source. - In order to make the secrets and advantages of the Benedict more versatile, the following examples will be described in detail with reference to the accompanying drawings. [Embodiment] A conventional signal converter can convert a data transmission having a large swing into a differential: 1. Money, in order to meet the demand for high-speed transmission of digits. The faster the A-switching ϋ operation rate, the more severe the electromagnetic interference, which will make the product turn around, or shorten the life. In view of this, embodiments of the present invention provide a signal converter to reduce (4) magnetic interference generated by a signal converter during high-speed operation to avoid HS-2008-0056-TW 30502twf.doc/n. The signal interpretation error 'has caused the product to rotate out of function. The embodiments of the present invention are explained in detail below with reference to the accompanying drawings, in which FIG. A circuit diagram of a signal converter in accordance with an embodiment of the present invention. Please refer to FIG. 1 ' The signal converter 10 ( ) provided by the embodiment mainly includes a first current source A1, a second current source A2, a first switching unit 102, a second switching unit 1〇4, and a first switching unit 102. The first capacitor unit 1〇6 and a second capacitor unit 1〇8. In addition, FIG. 1 further illustrates the load 110 externally connected to the signal converter 100. Here, the load 110 is, for example, a lower-level circuit of the signal = converter 1GG (for example, a signal receiver) or a signal transmission. For convenience, the equivalent circuit of FIG. 1 is further illustrated, and the equivalent circuit includes a resistor. R〇, capacitor CP1 and capacitor CP2. Private power has, power supply voltage VS. The first-switching unit 102 has a first end TM1 to a third end TM23. The second end M of the first switching unit 102 is the first switching unit. The second domain material H is connected to the two connected to the first to the first - switching t = ΤΜ 42 and the third end state 3 points _ second current source Α 2 _ in the ^ two end TM22 and the third end Τ hall. The capacitor unit 1〇6 of the first switching unit 1〇2 is connected to the grounding voltage GND1 to the first terminal TM41 of the switching unit, and the capacitor unit 1〇6 of the first switching unit 1〇2 is connected between the body, the TM21 and the ground voltage GND. 1378641 HS-2008-0056-TW 30502twf.doc/n The second capacitor unit 108 and the second current source A2 are connected in parallel with each other. The first current source A1 is used to provide a reference current II. The first switching unit 102 is configured to direct the reference current η to its second end 22 or third end 23 according to a differential input signal. On the other hand, the second switching unit 104 directs the reference current II flowing through the load 11 至 to the first terminal TM41 of the second switching unit 104 in accordance with the differential input signal 〇1. The second current source A2 is used to collect the reference current η. In this way, as the first switching unit 102 and the second switching unit 1〇4 switch the reference current II, the reference current η will flow through the load 11〇 and form a differential output signal at both ends of the load 110. D2, that is, the output signal D21 on the second end of the first switching unit 102 and the output signal D22 on the third end TM23. Here, the amplitude of the differential output signal D2 is smaller than the differential wheel. The amplitude of the signal 〇1 is entered, so the differential input signal converted by the signal converter 100 will satisfy the requirement of high-speed transmission. On the other hand, the first capacitor unit 〇6 is used to adjust the first capacitor unit according to the switching signal si. The capacitance value corresponding to 106. The second capacitance unit is configured to adjust the capacitance value corresponding to the second capacitance unit 1 〇 8 according to the switching signal S1, wherein the first capacitance unit 1 〇 6 and the second capacitance unit 1 〇 8 are more Referring to the frequency of the differential input signal D1 to control the switching signal illusion, the magnitude of the capacitance value corresponding to the first capacitor unit 106 and the second capacitor unit 〇8 is related to the frequency of the differential input signal D1. Capacitor unit and The capacitor unit 1〇8 will effectively filter out the surge of the first switch 1〇2 and the second switching unit just formed at the instant of switching the reference current ^ 1786641 HS-2008-0056-TW 30502twf.doc/n. In another embodiment of the present invention, the differential input signal D1 in FIG. 2 includes two input signals that do not overlap each other, and the first switching unit 1〇2 and the first switching unit 104 may each include two switches. For example, FIG. 2 is a circuit diagram of a signal converter in accordance with another embodiment of the present invention, and FIG. 3 is a diagram of a differential input signal and a differential output signal according to the present invention. Referring to FIG. 2 and FIG. 3, the differential input signal D1 in the embodiment includes a first input signal D11 and a second input signal 〇12 that do not overlap each other. wherein the signal is enabled at a high level, at a low level. The level is disabled. Therefore, the second input signal D12 is disabled during the period when the first input signal D11 is enabled, and the first input signal ^^" is disabled during the period when the second input signal D12 is enabled. And the two input signals are different when enabled. In addition, the first switching unit 1〇2 includes a first switch SW1 and a second switch SW2. The first end of the first switch SW1 is coupled to the first end TM21 of the switching unit 1〇2, and the second end of the first switch SW1 is connected to the second end TM22 of the first switching unit 102. The second switch SW2_W is connected to the first end TM2l of the first switching unit 1G2, and the second end of the second switch SW2 is coupled to the third end TM23 of the first switch. The switching unit 1〇4 includes a third switch SW3 and a fourth switch SW4. The first end of the third switch SW3 is lightly connected to the second end TM42 of the second switching unit 104, and the second end of the third switch SW3 is coupled to the first end TM41 of the second switching unit 104. The first end of the fourth switch SW4 is coupled to the third end TM43 of the second switching unit 1〇4, the fourth opening 9 1378641 HS-2008-0056-TW 30502tw-f.doc/n the second end box of the SW4 Connected to the first end TM41 of the second switching unit 1〇4. Further, the first to fourth switches SW1 to SW4 may be constituted by one to a plurality of transistors, respectively. The detailed operation of the first switching unit 102 and the second switching unit 1〇4 is considered. The first switch SW1 and the fourth switch SW4 switch their own on-state according to the first input signal D11, and the second switch SW2 and the second switch SW3 switch their own on-state according to the second input signal D12. Here, during the period when the first input signal D11 is enabled, the first switch SW1 and the fourth switch SW4 are turned on, and the second switch and the second gate SW3 are turned off. Therefore, the power supply provided by the first current source A1, 'Xin II will flow in from the first end of the turned-on first switch SW1, and flows through the negative g 110 to flow out from the second end of the turned-on fourth switch SW4. Further, the second current source A2 is collected. At this time, according to the flow direction of the reference current only, the second end TM22 of the first switching unit 102 can generate the high-precision output signal D21, and the third end of the first switching unit 102 can be generated to have Low level output signal D22. In contrast, when the second input signal is enabled, the second switch SW2 and the third switch SW3 are turned on and the first switch is torn and the switch SW4 is turned off. Therefore, the reference current II provided by the first current source A1 will flow in from the first end of the turned-on second switch SW2 and will be discharged from the second end of the turned-on third switch SW3, into the second=two The current source A 2 is collected. At this time, the second terminal TM22 of the first switching unit 1〇2 of the reference device according to the reference current will generate an HS-2008-0056-TW 30502twf.doc/n ^ signal ^21 having a low level, and The third end TM23 of the first-switching unit 102 will generate a round-out signal with a standing level. The switching value will continue to be repeated as the alternating of the first switch SW1 to the fourth switch sw4 < reference current 11 flows. Hunting the end of the load 11G will == signal D22, that is, the differential output signal 2 is the current value of the reference current n and the load of the load mm...product, that is, the round-out signal d21 and the output signal d22? As shown in Fig. 3, the differential output signal is the amplitude L1 of the second-field μ-, and under the action of the first capacitor electric, the differential output signal D2 two: ί of the glitch will be effectively Filter out. Secret phase =: Ϊ 'When the first switch-SW1 to the fourth switch SW4: change = temple, the voltage on the second end of the first switch _, and Ϊ; = _ on the second end of the Cao, its instant _^ ^^ Φ厫重重. In order to reduce the electromagnetic interference, the voltage caused by the upper and lower rushing of the four switches equivalent to the unit 1 〇 6 and the second capacitor unit (10) in this embodiment can be separated from the first current source A1 and the first The two current sources Α2 are generated, and the animal, the _capacitor unit 106 and the second capacitor unit 108 can be used to release the charge 2 and release the charge to alleviate the output signal to cut the switch at a higher frequency _ to the fourth switch sw4 Unit 1〇6 and second capacitor unit 1〇8 1 J / oun· HS-2008-0056-TW 30502twf.d〇c/n
It第電電流增強，此時將第-電容單元 合瞬門放出* / 所對應的電容值必須調小，以符 。瞬間放出大電流的需求。相對地 ： 四開關SW4以較低頻率切換時 放電電流減弱，㈣將第數減少且 私似— 電令早兀1〇6與第二電容單元 所對應的電容值必須調大，以 的頻率充放電，卿;峨_續1== D1 其中，第-電容單元106與第二電容單元⑽ =聯的多個電容，並可藉由調整電容的 =單元所對應的電容值的大小，列來說，圖= 實施例之第一電容單元的電路圖。請同時參 ^圖2及圖4,第一電容單元1〇6可包括多個第五開關 ^叫魏及多個第—電容cu〜αΝ，其中n為正整數。 一在此’多個第五開關SW51〜SW5N的第一端耦接至第 一切換單元102的第-端TM2卜多個第一電容⑶〜cw 分別與多個第五開關SW51〜SW5N —對一對岸，1中多個 容cn〜C1N的第-端各自輕接至對應的'第五開 ’且多個第-電容C11〜C1N的第二端輕接至接地電壓 GND。另外，切換信號S1可包括切換信號sii〜sin。 第一電容單元106可依據差動輸入信號D1的頻率來 控制切換信號S11〜S1N。當第一開關SW1至第四開關SW4 以較高頻率切換時，第一電容單元1〇6將依據切換信號 幻1〜S1N改變第五開關SW51〜SW5N的導通個數，以減少 第％»谷單元106中電谷並聯的個數，進而調整出適當的 12 HS-2008-0056-T iV 30502twf.doc/n 106 第一電容單元 108 第二電容單元 110 負載 1378641 A1 :第一電流源 A2 .弟二電流源 CPI、CP2、C11 〜C1N、C21 〜C2N :電容 R0 :電阻 TM21〜TM23 :第一切換單元的端點 TM41-TM43:第二切換單元的端點 VS :電源電壓 GND :接地電壓 II :參考電流 D1 :差動輸入信號 D11:第一輸入信號 D12 :第二輸入信號 D2 :差動輸出信號 D21、D22 :輸出信號 S1、Sli〜S1N :切換信號 SW1 〜SW4、SW51 〜SW5N、SW61〜SW6N :開關 U、L2 :振幅 15It is the first electric current enhancement. At this time, the ac-capacitor unit is released from the instantaneous gate* / the corresponding capacitor value must be adjusted to be small. The need to discharge large currents in an instant. Relatively: When the four switches SW4 switch at a lower frequency, the discharge current is weakened, (4) the number is reduced and the private number is similar. The capacitance value corresponding to the second capacitor unit must be increased, and the frequency is charged. Discharge, qing; 峨 _ _ 1 = = D1 where the first capacitor unit 106 and the second capacitor unit (10) = a plurality of capacitors, and by adjusting the capacitance = the size of the capacitor corresponding to the size of the column Said, Fig. = circuit diagram of the first capacitor unit of the embodiment. Please refer to FIG. 2 and FIG. 4 at the same time. The first capacitor unit 1〇6 may include a plurality of fifth switches, namely, Wei and a plurality of first capacitors cu~αΝ, where n is a positive integer. The first ends of the plurality of fifth switches SW51 to SW5N are coupled to the first end TM2 of the first switching unit 102, and the plurality of first capacitors (3) to cw are respectively paired with the plurality of fifth switches SW51 to SW5N. A pair of banks, the first ends of the plurality of capacitors cn~C1N are lightly connected to the corresponding 'fifth open' and the second ends of the plurality of first capacitors C11 to C1N are lightly connected to the ground voltage GND. In addition, the switching signal S1 may include switching signals sii to sin. The first capacitor unit 106 can control the switching signals S11 to S1N according to the frequency of the differential input signal D1. When the first switch SW1 to the fourth switch SW4 are switched at a higher frequency, the first capacitor unit 〇6 will change the number of conduction of the fifth switches SW51 to SW5N according to the switching signals illusion 1~S1N to reduce the %»谷The number of parallel valleys in unit 106, and then adjust the appropriate 12 HS-2008-0056-T iV 30502twf.doc/n 106 first capacitor unit 108 second capacitor unit 110 load 1378641 A1: first current source A2. 2nd current source CPI, CP2, C11~C1N, C21~C2N: Capacitor R0: Resistor TM21~TM23: End point of the first switching unit TM41-TM43: End point of the second switching unit VS: Power supply voltage GND: Ground voltage II: reference current D1: differential input signal D11: first input signal D12: second input signal D2: differential output signal D21, D22: output signal S1, Sli~S1N: switching signals SW1 to SW4, SW51 to SW5N, SW61~SW6N: switch U, L2: amplitude 15