M294158 ^ 八、新型說明： 【新型所屬之技術領域】 本創作涉及一種順向式電源轉換器的控制電路，更具體而言，涉及一種改進電 源轉換效率的順向式電源轉換器的同步整流器控制電路。 【先前技術】 電源轉換器常用於將一未調節的電源變換成定電壓源和/或定電流源。具有一初 級繞組和一次級繞組的變壓器通常用於電源轉換。在一典型應用中，初級繞組耦接 到一未調節的直流電壓源，且一切換裝置連接到初級繞組以導通和截止直流電壓源 與初級繞組之間的傳導。一整流二極體連接到次級繞組以將從初級繞組變換來的能 1整流成直流電壓。然而，在整流二極體兩端的順向電壓降卻造成不可避免的傳導 損耗，並使得整流二極體成為產生損耗的關鍵元件。為解決功率損耗問題，大多採 用低導通阻抗電晶體來取代整流二極體並應用電源轉換器的同步整流(Synchr_s Rectifying)技術改善之。最近，EdgarAbd〇uUn在題為“別喊如福加丽d⑺請伽 with synchronous rectiflcation and delay 价〇曲 in phase l〇cked 1〇〇p”的美國專利第 M2MG5號中提出-種同步整流技術。然而，上述現有同步整流技術的缺點是在輕 載條件下會降低電轉換效率。此外，在重貞載玉作_可紐生交叉傳導。 第1圖說明-具有同步整流H的習知軸式電轉觀。順向式電源轉換器包 括-變壓器10、多個切換裝置2〇、3〇，其中多個切換裝置2〇、3〇係用於控制在變 壓器10的初級繞組與-輸入電壓源ViN之間的傳導。應用多個二極體25和35來將 减繞組的電感能量收回到輸入電壓源V1N。用作同步整流器的兩個電晶體⑽、70 和妾到變壓器10的次級繞組。第—電晶體6G祕在次級繞組的—第—端與一接地 7之間n體70從次級繞組的―第二端連接到接地端。—電感器轉接在 =繞組的第二端與電源轉換㈣輸出端之間…輸出電容把連接於電源轉換器的 輸出端與接地端之間。 第1A圖綠不白知電源轉換器的第一工作階段。在這個階段中 3〇導通後，能量係經由變壓哭则口雷^ 〇Λ心— 俠衣置川和 文壓②10和電感$ 80從輸入電壓源Vm向電源轉# 出端傳導。電晶體仰在其寄生二極體6S導通後導通，用作同步紐器轉換益的輸 第1B圖緣不習知電源轉換器的第二工作階段。在這個階段中，切換裝置2㈣ M294158 截止後。存儲在電感器80中的能量經由電晶體70的寄生二極體75向輸出端連續 電。電晶體70在其寄生二極體75導通後導通，用作同步整流器。 、$放M294158 ^ VIII. New Description: [New Technology Field] This paper relates to a control circuit for a forward power converter, and more particularly to a synchronous rectifier control for a forward power converter with improved power conversion efficiency. Circuit. [Prior Art] A power converter is often used to convert an unregulated power supply into a constant voltage source and/or a constant current source. A transformer with a primary winding and a primary winding is typically used for power conversion. In a typical application, the primary winding is coupled to an unregulated DC voltage source and a switching device is coupled to the primary winding to conduct and disable conduction between the DC voltage source and the primary winding. A rectifying diode is coupled to the secondary winding to rectify energy 1 converted from the primary winding to a DC voltage. However, the forward voltage drop across the rectifying diode causes inevitable conduction losses and makes the rectifying diode a critical component for loss. In order to solve the power loss problem, a low on-resistance transistor is often used instead of the rectifying diode and the power converter's synchronous rectification (Synchr_s Rectifying) technique is used to improve it. Recently, Edgar Abd〇uUn proposed a synchronous rectification technique in the U.S. Patent No. M2MG5 entitled "Don't shout, such as 福加丽d(7) 伽加 with synchronous rectiflcation and delay price in phase l〇cked 1〇〇p". However, the above-mentioned conventional synchronous rectification technique has a drawback in that the electric conversion efficiency is lowered under light load conditions. In addition, in the heavy load of jade _ can be a cross conduction. Figure 1 illustrates a conventional axial electroconversion with synchronous rectification H. The forward power converter comprises a transformer 10, a plurality of switching devices 2〇, 3〇, wherein a plurality of switching devices 2〇, 3〇 are used for controlling between the primary winding of the transformer 10 and the input voltage source ViN. Conduction. A plurality of diodes 25 and 35 are applied to retract the inductive energy of the windings to the input voltage source V1N. The two transistors (10), 70 used as synchronous rectifiers and the secondary windings of the transformer 10 are used. The first transistor 46G is between the first end of the secondary winding and a ground 7 and the n body 70 is connected from the second end of the secondary winding to the ground. - The inductor is switched between the second end of the = winding and the power conversion (four) output... The output capacitor is connected between the output of the power converter and the ground. Figure 1A shows the first stage of the work of the power converter. In this stage, after the conduction of 3〇, the energy system is crying through the pressure change, and the heart is smashed--Xin Yi-Jing and Wen 210 and Inductor $ 80 are transmitted from the input voltage source Vm to the power source. The transistor is turned on after its parasitic diode 6S is turned on, and is used as the second working stage of the power converter. In this phase, switching device 2 (4) M294158 is turned off. The energy stored in the inductor 80 is continuously supplied to the output terminal via the parasitic diode 75 of the transistor 70. The transistor 70 is turned on after its parasitic diode 75 is turned on, and functions as a synchronous rectifier. $ put
順向式電源轉換器通常具有二種不同的工作模式，即非連續工作模式和連鲼 作模式。在連續工作模式中，能量仍保持在電感器80中，亦即，下一個工作週 電感器80釋放的電流達到零之前就開始了。因為在第二工作階段期間，電晶體％ 被導通用作同步整流器，所以，在下-週細始後可能發生交叉傳導，如第2Α圖中 所及月其中將經由電晶體70和寄生二極體65使得次級繞組發生短路。在交二傳 導期間，將產生電磁干擾(electromaSnetic interference)，並且將嚴重減少電晶體％ 6〇的使用壽命。相反地，在非連續工作模式中，在下一週期開始之前，存儲在電感 器8〇中的所有能量已完全被釋放完畢。因此，沒有感應電壓保持在電感器8〇中: 阻擔輸出電容器85的能量放電回到變壓器1〇。 如第2B圖中所說明，當電源轉換器在輕負載條件下處於非連續工作模式中時， 在=換瞬間電感器8〇的能量將被完全釋放，且一反向電流將從輸出電容器粘放電 變壓H 1G。反向電流產生神損耗並大幅降低電轉換的效率。本創作的目的b 提供-_於同步整流的控制電路，其在連續工作模式和非連.作模式 = 高工作效率的表現。 ’ 【新型内容】 -電路供電源轉換H的同步整流，包括—具有—初級繞組和—次級繞組的變壓 器。次級繞組包括第-端和第二端。當_變壓器時，在鍾器的次級繞組的第二 端和第-端之間產生-切換電壓。—可飽和電感器從變縫次級繞組的第二端輕接 到-第三端。-第-電晶體從變壓器的次級繞組的第_端雛到—接地端。此外， -第二電晶體從第三端_到接地端。第—電晶體和第二晶體管用作同步整流器。 -電感器從第三端_到電源轉換器的—輸出端。此外，—電流感測裝置響應電感 器的-切換電流而產生-電流信號。一控制電路連接到第三端並接收切換電壓和電 流信號，以產生分別用於驅動第-電晶體和第二電晶體的—第_控制㈣和一第二 控制信號。可飽和電«提供—延遲時間，其用於當切換電壓產生時抑制從麵器 的次級繞減第二端流向第二電晶_電流。科，_個二極體從控龍路連接到 第三端，其用於檢測第三端上的電壓並提供第二控制信號。 上述說明僅是本創作技術内容的概述，為了能夠 1清楚了解本創作的技術手 段’並依照說扣實施，以τ以本創作的較佳實施例配合關說明如後。 M294158 :實施方式】 第3圖說明根據本創作的第—實施綱同步整流電路。上述電路包括— 初級繞組和-次級繞組的變壓器1G。次級繞組包括—第_端和—第二端。—ς換電 壓Vs依據變壓器1〇的切換，在次級繞組的第二端和第一端之間產生。一可飽和 感器50從次級繞組的第二端遠接钊一笙— _ η ^ *知運接到一第二端。一電晶體6〇從次級繞組的第一端 接到接地端i曰曰體70從第二端連接到接地端。一電感器8〇從第三端連接到電 源轉換器_出端，以產生輸出„Vq。—電流感難置依據—切換電流“而產 生-電流信號。-控制電路⑽用來導通/截止電晶體⑽和7()。控制電路i⑽接收 切換電壓VS和電流信號，用以產生分別用以驅動電晶體6〇和電晶體7〇的一第一控 制信號S!和-第二控制信?虎&。控制電路1〇〇包括一連接到次級繞組第二端的聰+ 端和-連接到次級繞組第-端❹ET-端。控制電路1〇_ GND端連接到接地參考。 控制電路100更包括IN1端和IN2端、輸出端〇UT1和輸出端〇UT2。控制電路⑽ 的ΙΝ1端經由一二極體90連接到電晶體7〇以檢測電晶體7〇的一電壓Ve。m2端 用來檢測電流信號。輸出端OUT1和OUT2產生分別用於切換電晶體6〇和70的第 一控制信號Si*第二控制信號S2。當切換信號產生時，變壓器10的電流流經可飽 和電感器50、電感器80、電源轉換器的輸出端和一二極體65。二極體沾可為電晶 體60的寄生二極體和/或外部二極體。在切換信號產生時，可飽和電感器5〇提供一 延遲時間TD，其抑制從變壓器1〇流向電晶體7〇的電流並保護電晶體7〇。 弟4圖δ兒明根據本創作控制電路1〇〇的第一實施例，控制電路1〇〇包括一比較 器110，比較器110的一正輸入端經由一參考電壓（threshold) 120連接到DET+端。 DET+端更經由一電阻器40耦接到變壓器1〇次級繞組的第二端。比較器的負輸 入端連接到DET-端。DET-端更經由一電阻器45耦接到變壓器10次級繞組的的第一 端。一比較器111的一正輸入端經由一參考電壓123耦接到DET+端。比較器111的 一負輸入端連接到DET-端。一比較器112的一正輸入端經由一參考電壓125搞接到 DET-端。比較器112的一負輸入端連接到DET+端。一比較器115的一正輸入端耦 接到一參考電壓VR1。比較器115的一負輸入端耦接到IN1端。IN1端更耦接到第三 端以檢測電晶體70的電壓。一電流源129耦接到比較器115的負輸入端。一比較器 116的一正輸入端連接到一參考電壓VR2。比較器116的負輸入端連接到IN2端以接 收電流信號。一正反器155產生第一控制信號S〗，其中第一控制信號St由比較器110 啟用並由比較器111禁用。正反器156產生第二控制信號S2。其中第二控制信號S2 由112和比較器115啟用並由比較器111或比較器116禁用。一電路包括多個及閘 M294158 160、161和多個反相器162、163用來保證在啟用第〆控制信號S!之前禁用第二控 制信號S2，並保證在啟用第二控制信號S2之前禁用第一控制信號Si。 因此，在切換電壓Vs高於參考電壓120後，第一控制信號Si即啟用。一旦切換 電壓Vs低於參考電壓123，第一控制信號S〗即禁用。一旦電晶體70的電壓低於參 考電壓VRi並且切換電壓Vs低於參考電壓125，第二控制信號S2即啟用。只要電流 信號低於參考電壓VR2和/或切換電壓Vs高於參考電壓123,第二控制信號S2即禁用。 第5圖說明根據本創作第一實施例在連續工作模式中工作的同步整流的關鍵波 形。在下一切換週期開始前，電感器80仍保持能量。可飽和電感器50提供延遲時 間TD。在延遲時間TD期間，切換電壓vs被抑止傳遞到第三端且切換電流Isw被抑 止從變壓器10流出。因此，在切換電流1^開始之前，可截止電晶體70。 喔| 第6圖說明根據本創作的第一實施例在非連續工作模式中工作的同步整流的關 鍵波形。在切換電壓Vs再次對電感器80充電之前，電感器80儲存的能量已完全釋 放。非連續工作模式一般用於輕載和無載條件下。在電感器8〇被放電到零之前，令 電晶體70截止，以在輕載操作的情況下防止電容器85的能量經由電晶體7〇放電。 第7圖說明本創作的第二實施例。此實施例以電阻器95用以作電流感測裝置， 其用以將切換電流Isw轉換為電壓信號供控制電路1〇〇使用。第8圖說明根據本創 作的第三實施例的電路。配備—電流感測裝置2⑽以將切換電流“轉換為電壓信 號。 第9圖㈣根據Η 8所林創作的實闕的電流❹丨裝置2⑽。電流感測裝置 200包括一變流器1S、多個二極體210〜213、一電阻器215和-電容器22〇。電流 φ 翻裝4 200轉換切換電流Isw並產生-信號供控制電路100的仍2端。 以上所述，僅是本創作的較佳實施例，然並非用以對本創作作任何形式上之限 制’雖然本創作已啸佳實_祕如上，⑽麟心限定本解，任何孰悉本 技術的人貝’在秘離本創作的技術範_，t可上述減的結構及技術内容 作出些許更動或修飾成為等同變化的等效實施例，凡是未脫離本創作技術内容，依 據本創作技術實質所作的任何簡單修改、等同變化與修飾，均應屬於本創 圍内。 【圖式簡單說明】 在此所附之圖表是用來清楚描述本創作，並引用與包含詳細規格的_部份，以下的 •M294158 圖表本創作的，例，並配合詳細說明部分，用 第1圖說明-具有同步整流器的習知順向式電源轉乍的原理 第1A圖說明習知電源轉換器的第一工作階段。 第1B圖說明習知電源轉換器的第二工作階段。 第2A圖說明習知電源轉換器在連續工作模式中的交叉傳導操作。 和從 第2B圖說明在輕負載條件期間在非連續工作模式操作的習知電源轉換器 輸出電容器到變壓器的反向電流放電操作。 、° 第3圖是根據本創作的第一實施例的同步整流電路的示意圖。 第4圖說明根據本創作的第一實施例產生驅動信號供同步整流器的控制電路。Forward-to-power converters typically have two different modes of operation, the discontinuous mode of operation and the mode of operation. In the continuous mode of operation, energy remains in the inductor 80, i.e., before the current released by the inductor 80 at the next working cycle reaches zero. Since the transistor % is turned on as a synchronous rectifier during the second working phase, cross conduction may occur after the next-week start, as in the second half of the figure, which will pass through the transistor 70 and the parasitic diode. 65 causes a short circuit in the secondary winding. During the second pass, electromagnetic interference (electromaSnetic interference) will occur and the lifetime of the transistor will be severely reduced. Conversely, in the discontinuous mode of operation, all of the energy stored in inductor 8A has been completely released before the start of the next cycle. Therefore, no induced voltage remains in the inductor 8: The energy of the output capacitor 85 is discharged back to the transformer 1〇. As illustrated in Figure 2B, when the power converter is in a discontinuous mode of operation under light load conditions, the energy of the inductor 8〇 will be completely released at the moment of the change, and a reverse current will stick from the output capacitor. The discharge is transformed into H 1G. Reverse currents generate God's losses and greatly reduce the efficiency of electrical conversion. The purpose of this creation is to provide a control circuit for synchronous rectification, which is characterized by continuous operation mode and non-connection mode = high work efficiency. [New content] - Synchronous rectification of circuit power supply switching H, including - transformer with - primary winding and secondary winding. The secondary winding includes a first end and a second end. When the transformer is turned on, a -switching voltage is generated between the second end and the first end of the secondary winding of the clock. - The saturable inductor is lightly connected from the second end of the variable pitch secondary winding to the - third end. - The first transistor is from the _th end of the secondary winding of the transformer to the ground. Furthermore, the second transistor is from the third end _ to the ground. The first transistor and the second transistor are used as synchronous rectifiers. - The inductor is connected from the third terminal _ to the power converter. In addition, the current sensing device generates a current signal in response to the -switching current of the inductor. A control circuit is coupled to the third terminal and receives the switching voltage and current signals to produce - _ control (4) and a second control signal for driving the first transistor and the second transistor, respectively. The saturable electric energy «provides" a delay time for suppressing the secondary winding from the second winding to the second electric crystal current when the switching voltage is generated. The _ diodes are connected from the control channel to the third terminal, which is used to detect the voltage on the third terminal and provide a second control signal. The above description is merely an overview of the technical content of the present invention. In order to be able to clearly understand the technical means of the present invention and to implement it according to the deduction, the description of the preferred embodiment of the present creation is as follows. M294158: Embodiment] Fig. 3 illustrates a synchronous rectifier circuit according to the first embodiment of the present invention. The above circuit includes a primary winding and a secondary winding transformer 1G. The secondary winding includes a -th terminal and a second end. The switching voltage Vs is generated between the second end of the secondary winding and the first end in accordance with the switching of the transformer 1〇. A saturable sensor 50 is remotely connected from the second end of the secondary winding to a second end. A transistor 6 is connected from the first end of the secondary winding to the ground terminal i from the second end to the ground. An inductor 8 is connected from the third terminal to the power converter_out terminal to generate an output „Vq.—the current sense is difficult to set—switch the current to generate a current signal. - A control circuit (10) is used to turn on/off the transistors (10) and 7(). The control circuit i (10) receives the switching voltage VS and the current signal for generating a first control signal S! and a second control signal, respectively, for driving the transistor 6A and the transistor 7A. The control circuit 1A includes a Cong+ terminal connected to the second end of the secondary winding and a - terminal ET-terminal connected to the secondary winding. The control circuit 1 〇 GND terminal is connected to the ground reference. The control circuit 100 further includes an IN1 terminal and an IN2 terminal, an output terminal 〇UT1, and an output terminal 〇UT2. The ? terminal of the control circuit (10) is connected to the transistor 7A via a diode 90 to detect a voltage Ve of the transistor 7?. The m2 terminal is used to detect the current signal. The output terminals OUT1 and OUT2 generate a first control signal Si* second control signal S2 for switching the transistors 6A and 70, respectively. When the switching signal is generated, the current of the transformer 10 flows through the saturable inductor 50, the inductor 80, the output of the power converter, and a diode 65. The diode may be a parasitic diode and/or an external diode of the electromorph 60. When the switching signal is generated, the saturable inductor 5A provides a delay time TD which suppresses the current flowing from the transformer 1 to the transistor 7 and protects the transistor 7A. According to a first embodiment of the present creative control circuit 1A, the control circuit 1A includes a comparator 110, and a positive input terminal of the comparator 110 is connected to the DET+ via a reference voltage (threshold) 120. end. The DET+ terminal is further coupled to the second end of the secondary winding of the transformer 1 via a resistor 40. The negative input of the comparator is connected to the DET- terminal. The DET-terminal is further coupled to the first end of the secondary winding of the transformer 10 via a resistor 45. A positive input of a comparator 111 is coupled to the DET+ terminal via a reference voltage 123. A negative input of comparator 111 is coupled to the DET- terminal. A positive input of a comparator 112 is coupled to the DET- terminal via a reference voltage 125. A negative input of comparator 112 is coupled to the DET+ terminal. A positive input of a comparator 115 is coupled to a reference voltage VR1. A negative input of comparator 115 is coupled to the IN1 terminal. The IN1 terminal is further coupled to the third terminal to detect the voltage of the transistor 70. A current source 129 is coupled to the negative input of comparator 115. A positive input of a comparator 116 is coupled to a reference voltage VR2. The negative input of comparator 116 is coupled to the IN2 terminal to receive a current signal. A flip flop 155 generates a first control signal S, wherein the first control signal St is enabled by the comparator 110 and disabled by the comparator 111. The flip flop 156 generates a second control signal S2. The second control signal S2 is enabled by 112 and comparator 115 and disabled by comparator 111 or comparator 116. A circuit includes a plurality of AND gates M294158 160, 161 and a plurality of inverters 162, 163 for ensuring that the second control signal S2 is disabled prior to enabling the second control signal S! and is guaranteed to be disabled prior to enabling the second control signal S2 The first control signal Si. Therefore, after the switching voltage Vs is higher than the reference voltage 120, the first control signal Si is enabled. Once the switching voltage Vs is lower than the reference voltage 123, the first control signal S is disabled. Once the voltage of the transistor 70 is lower than the reference voltage VRi and the switching voltage Vs is lower than the reference voltage 125, the second control signal S2 is enabled. The second control signal S2 is disabled as long as the current signal is lower than the reference voltage VR2 and/or the switching voltage Vs is higher than the reference voltage 123. Figure 5 illustrates the key waveform of synchronous rectification operating in a continuous mode of operation in accordance with the first embodiment of the present invention. The inductor 80 remains energized until the beginning of the next switching cycle. The saturable inductor 50 provides a delay time TD. During the delay time TD, the switching voltage vs is suppressed from being transmitted to the third terminal and the switching current Isw is suppressed from flowing out of the transformer 10. Therefore, the transistor 70 can be turned off before the switching current 1^ starts.喔 | Fig. 6 illustrates a key waveform of synchronous rectification operating in a discontinuous mode of operation in accordance with the first embodiment of the present invention. The energy stored by the inductor 80 is completely released before the switching voltage Vs charges the inductor 80 again. The discontinuous mode of operation is typically used under light load and no load conditions. Before the inductor 8 is discharged to zero, the transistor 70 is turned off to prevent the energy of the capacitor 85 from being discharged via the transistor 7 在 in the case of light load operation. Figure 7 illustrates a second embodiment of the present work. In this embodiment, the resistor 95 is used as a current sensing device for converting the switching current Isw into a voltage signal for use by the control circuit 1 . Figure 8 illustrates a circuit in accordance with a third embodiment of the present invention. Equipped with a current sensing device 2 (10) to "convert the switching current into a voltage signal. Figure 9 (d) is based on the actual current device 2 (10) created by the forest. The current sensing device 200 includes a converter 1S, more Two diodes 210 to 213, a resistor 215 and a capacitor 22 〇. The current φ flips 4 200 to convert the switching current Isw and generates a signal for the two ends of the control circuit 100. The above is only the creation of the present invention. The preferred embodiment is not intended to impose any form limitation on the creation. Although the creation has been Xiaojia Shi _ secret as above, (10) Lin Xin limited the solution, any person who knows the technology is in the secret The technical norm, t can be modified or modified to be equivalent to the equivalent embodiment of the above-mentioned structural and technical content. Any simple modification or equivalent change made according to the essence of the creative technology without departing from the technical content of the present invention. Modifications should be included in this creation. [Simplified illustration] The chart attached here is used to clearly describe the creation, and to quote and include the detailed specifications of the _ part, the following • M294158 chart creation For example, with the detailed description, the first diagram illustrates the principle of a conventional forward power supply with a synchronous rectifier. Figure 1A illustrates the first stage of operation of a conventional power converter. Figure 1B illustrates a conventional power conversion. Second stage of operation. Figure 2A illustrates the cross-conduction operation of a conventional power converter in a continuous mode of operation. And from Figure 2B illustrates a conventional power converter output operating in a discontinuous mode of operation during light load conditions. Reverse current discharge operation of the capacitor to the transformer. Fig. 3 is a schematic diagram of the synchronous rectification circuit according to the first embodiment of the present invention. Fig. 4 is a view showing the generation of a drive signal for the synchronous rectifier according to the first embodiment of the present invention. Control circuit.
第5圖說明根據本創作的第一實施例用於連續工作模式中的電源轉換器的同步 整流的多個關鍵波形。 第6圖說明根據本創作的第一實施例用於非連續工作模式中的電源轉換器的同 步整流的多個關鍵波形。 第7圖說明根據本創作的第二實施例的同步整流電路。 第8圖說明根據本創作的第三實施例的同步整流電路。 第9圖說明根據本創作的第三實施例包括一用於產生電流信號的變流器的電流 感測裝置。 【主要元件符號說明】 20、30 :切換裝置 25、35、90 :二極體 40、45、95、215 :電阻器 5〇 :可飽和電感器 60'7〇 :電晶體 65、75 :寄生二極體 8〇 :電感器 85 :輸出電容 100 :控制電路 110、111、112、115、116 :比較器 •M294158 120、123、125 ·•參考電壓 129 :電流源 155、156 ··正反器 160、161 :及閘 162、163 :反相器 200 :電流感測裝置 210〜213 :二極體 220 :電容器Fig. 5 illustrates a plurality of key waveforms for synchronous rectification of a power converter in a continuous operation mode according to the first embodiment of the present invention. Figure 6 illustrates a plurality of key waveforms for synchronous rectification of a power converter in a discontinuous mode of operation in accordance with a first embodiment of the present invention. Fig. 7 illustrates a synchronous rectification circuit according to a second embodiment of the present creation. Fig. 8 illustrates a synchronous rectification circuit according to a third embodiment of the present creation. Figure 9 illustrates a current sensing device including a current transformer for generating a current signal in accordance with a third embodiment of the present invention. [Main component symbol description] 20, 30: switching device 25, 35, 90: diode 40, 45, 95, 215: resistor 5 〇: saturable inductor 60'7 〇: transistor 65, 75: parasitic Diode 8〇: Inductor 85: Output Capacitor 100: Control Circuits 110, 111, 112, 115, 116: Comparator • M294158 120, 123, 125 • Reference Voltage 129: Current Sources 155, 156 • Positive and Negative And 160, 161: inverter 200: current sensing device 210~213: diode 220: capacitor
Isw ·切換電流 S!:第一控制信號 s2:第二控制信號 TD :延遲時間 vE:電壓 Vin :輸入電壓源 V〇 :輸出電壓 vs:切換電壓Isw ·Switching current S!: First control signal s2: Second control signal TD : Delay time vE: Voltage Vin : Input voltage source V〇 : Output voltage vs: Switching voltage