TWI294716B - - Google Patents

Description

Ί 294716 IX. Description of the invention: [Technical field to which the invention pertains] In general, the present invention pertains to power electronics (electrical electrons), and more particularly to a synchronous rectification circuit system having self-driving capability (SdfDriven). [Prior Art] Synchronous rectification is widely used in low-voltage, high-current DC-to-DC converters due to low voltage. The on-state voltage of the field effect transistor (M0SFET) is reduced by the Schottky diode (Sch〇ttky diode). There is a lot of turn-by-turns, so the power MqSFET is used as a synchronous rectification to achieve improved overall conversion age. However, the performance of this step-by-step rectification side is not always superior to that of the Φ, 宵 宵 一 一 , , , , , , , , , , , , , , , , , , , , , , , , , , , , , At present, there are two main methods for controlling the synchronous rectifier: the self-driving method and the controller driving method (Controller Driven). In the isolated circuit architecture (Is〇lated T〇p〇1〇gy), the controller driving method usually has It is more complicated than the corresponding self-driving method, and the cost is more expensive, so it is not suitable. There are two types of self-driving laws, voltage-driven (10) such as #Driven Meth〇d:) and Current Driven Method, current-driven synchronous rectifiers use Current Sense to control the switching time. The current-driven rectifier must be additionally energized. k Inductive components such as current sense transformers or current sense MOSFETs will increase circuit complexity. Voltage-driven synchronous rectification is more attractive because of its simplicity. The drive signal used to drive the synchronous rectifier can be derived from the main transformer winding coil or the coupled winding on the output inductor. Among the various Topology technologies, the forward line architecture (Forward) Topology) is one of the best architectures for low-voltage power conversion lines because it is the simplest derivation architecture from buck lines; however, forward-going line architectures have some drawbacks when using synchronous rectifier switches, such as An existing technology (pri〇r Art) shown in Figure (A) uses the same The rectifier forward converter uses a secondary winding of the main transformer to drive the synchronous rectifier, wherein the forward rectifier switch S1 is connected to the idler of the flywheel 5 1294716 (Freewheding) rectifier _ S2 To the main transformer secondary winding coil SEC (five) two joints, the alternating voltage generated by the two pill winding wires ffl SEC and the converter main switch S are driven to the commutator switch Μ and the flywheel (Freewheeiing) rectifier switch S2 'in the - In Figure (A), when the converter main switch s is turned on, the voltage V(SEC) generated by the secondary winding coil sEC is positive with respect to the gradation gamma of the forward rectifier switch S1. In this way, the forward rectifier switch S1 can be turned on, at the same time, the output of the Wei Lf current • 'flow through the forward rectifier switch S Bu-like this period is called "Duty", time, in - The complete switching period (Switching Cycle) is referred to as the D period, because it is during this period. Θ 'Convert $ main switch S is performing work and the - secondary power is transmitted to the secondary side of the converter. Turn off Social s, Magnetizing CuiTent will flow through the magnetic reset (MR: Magnetic Reset) circuit, the voltage of the secondary winding SEC of the transformer v (sec) will change the polarity (Polarity), so turn off the forward rectifier switch The Fr_heding rectifier switch s2 is turned on at the same time, and the output inductor Lf current flows through the flywheel (Freewheding) rectifier switch S2. This period is usually called the flywheel period (Freewheding peri〇d 〇ftime) due to the flywheel (Freewheeling) The rectifier switch S2 is performing its work, so all of the inductance Lf current is passing through this freewheeling rectifier switch S2. The main disadvantage of this line structure is that when the magnetizing current is reset and the reset is zero, the body diode of the Freewheding rectifier switch is turned on. In this case, as shown in the first figure (B), the voltage V(SEC) of the secondary side of the transformer becomes zero, and the period in which this phenomenon occurs is generally called the static time (fu time), and the static time is determined. __, New Zealand is flowing through this - the body diode of the flywheel rectifier off s2' compared with the general fast recovery diode (Fast Rec〇very Di〇de), the body diode has a higher pressure Reduced and poor reverse recovery characteristics (Reverse Rec〇vejy Characteristics) 〇 Therefore, during this dead time, the synchronous rectifier losses are much higher than the traditional Schottky diode rectifiers. Since the advantages of the synchronous rectifier are greatly impaired due to the conduction of the body diodes of the static time, the following two remedies can avoid the phenomenon that the body diode is turned on during the static time. 6 1294716 The first method is found in the prior art of the US Patent No. 6,377,477 (Prior μ). The second diagram (A) and the second diagram (B) show the equivalent diagram and the associated waveform time diagram. The main concept is that the gate charge of the Freewheeling rectifier switch S5 is changed within the dead time by using an external diode D1, so that the flywheel rectifier switch S5 can remain conductive during the period ( Turn On) to prevent the body diode from being turned on. This situation can be seen in the second diagram (b), where a period of time is indicated as "dead time", at which point Vgs (S5) (the gate voltage of the flywheel rectifier switch S5) remains high, so The main body diode of the flywheel rectifier switch S5 is prevented from being turned on. The second remedy involves inserting a DC bias in series into a freewheeling rectifier, switching the gate, thereby enabling the flywheel rectifier to be switched on and off. The effect of maintaining conduction in the dead time I. This method can be found in the US Pat. No. 6,822,882, the equivalent diagram of which is shown in the third figure (4), in which a separate third, winding must be used. The coil ship is provided with a flywheel rectifier switch S7 gate drive signal Vsec3 to turn off the flywheel rectifier switch S7 during the on time of the main switch S6; if there is no such third winding coil SEC3, the second remedy is not It may be successfully implemented, because the tertiary winding coil SEC3 only needs to load a very small amount of gate charging current, as long as a very fine gauge (four) wire can act, making the main transformer During the manufacturing process, the manufacturing cost of the newly added three-coil SE^3 coil is actually equal to zero. The third figure (8) is one of the specific lines, the implementation mode, in which the inductor 2 is required; 1, resistance and electricity | Rong jzd can form the hardware part of DC compensation (v〇ffset), at the same time, in this case, the second full high output source +Vout (if the voltage is just high enough, it is rare, because Here we discuss = low output voltage and high current output) as the main power supply, and through the bias resistors (bias resistorms to implement charging, this required % compensation function (10) (four) is OK' Its function is to maintain the flywheel (Freewhedin switch rectifier W gate in the static = _ead time) to maintain the high position. If the output voltage + ν_ can not be high enough to pass the bias group Rbs to the second pole The body ZD〇1 bias will require an external external positive bias source with sufficient high voltage (extemal p〇sMve bias _ (4) to make this second rescue mode effective, so more cost is required. SUMMARY OF THE INVENTION The present invention The main purpose is to overcome the problem that the body diode is turned on in the dead time flywheel 7 1294716 (Freewheeling) rectifier switch. It is enough to use the single-signal diode small resistor control pole to achieve the flywheel rectifier switch. The main objective of static determination = h issuance, etc. Another object of the present invention is to use the number of components to be the minimum amount compared to the number used in the prior art of the patent application 2882. Since the operating principle is basically different from the two prior art described above, the difference in operating principle makes this simple gate driving circuit the most successful compared to the two prior art actual circuits described above: • Benefits By. a [Embodiment] • In order to enable the reviewing committee to understand the circuit architecture of the present invention and the overall operation mode, the following diagram is described as follows: The fourth figure (8) shows that the first actual circuit to which the present invention is applied is The synchronous rectifier circuit is driven by the converter itself. The fourth diagram (B) is the waveform time diagram in the circuit diagram of the fourth diagram (A). As shown in the fourth figure (7), the transformer τ includes a secondary winding coil Pri, a secondary winding SEC4 coil, and a driving winding SEC5 coil, and the driving winding coil SEC5 drives only the gate of the flywheel (Freewheding) rectifier switch S10. Using a very fine gauge wire (equivalent to low cost), the primary winding coil Pri has a positive terminal wire connected to the power Vin positive terminal, and a negative terminal wire connected to a main switch S8 Drain connector, the main switch The source connector of S8 is connected to the negative pole of the power supply Vin, ^ the primary winding coil SEC4 and the driving winding coil | § EC5 has the same polarity as the positive terminal of the primary winding coil Pri, the forward rectifier The switch S9 and the flywheel rectifier switch S10 are synchronous rectifier MOSFET transistors, and the source terminals of the two transistors are interconnected to each other and to the positive terminal of the drive winding coil SEC5, and the drain connector of the forward rectifier switch S9 is connected twice. The negative terminal of the winding coil SEC4, and the gate terminal of the forward rectifier switch S9 is connected to the positive terminal of the secondary winding coil SEC4 (for those skilled in the art, This embodiment is significant penetration plus embodiment is not driven more emphasis on the concept of self-display embodiment, an actual implementation may involve a voltage divider with a new subject to the drive circuit in order to facilitate achieving this concept). The drain terminal of the Freewheeling rectifier switch S10 is connected to the positive terminal line of the secondary winding coil SEC4, and the gate terminal of the flywheel rectifier switch S10 is connected to the resistor R, and the other end of the resistor R It is connected to the cathode (Cathode) of the Zener diode Zener. The anode of the Zener 8:1294716 body is connected to the negative terminal of the driving winding coil SEC5, and the inductor L3 and the capacitor C3 form an output. The filters are connected as shown in the diagram, where the resistance 汜 represents the external load. In actual operation, please refer to the fourth figure (B). From t=tO to t=tl, the main switch S8 is turned on. The voltage of the secondary winding coil VSEC4 is positive voltage, and the negative winding of the winding coil SEC5 will be driven. The negative voltage is generated to cause the Attenuator Zener to collapse (Avalanche), so the gate voltage Vgs(10) of the flywheel rectifier switch S10 will reach the negative potential and the flywheel rectifier switch s 1 关 will be turned off. (This transition time from the conduction state to the non-conduction state (transiti〇n time) length. Can be controlled by the resistor R, this control ability has reduced the peak reverse polarity of the S10 through the flywheel (Freewheeling) (Spiking Reverse Voltage) The benefits of the phenomenon, and help reduce the spectral voltage (Ringing V〇ltage) by a certain degree. At this time, the current of the output inductor L3 flows through the forward rectifier switch S9. The main switch S8 starts at t=tl Turned off, so the magnetizing current flows through the magnetic reset (MR) circuit. The voltage applied to the gate of the forward rectifier switch S9 is reversed. The forward rectifier switch S9 is turned off. The electric current of the negative end line of the winding coil SEC5 is positive, and the gate of the freewheeling rectifier switch sio is charged to the voltage of Vsec5 through the Zener diode Zener, thus making the flywheel rectifier switch sl Turning on 'and causing the output inductor L3 current to flow through the flywheel rectifier switch si〇. The transformer T reset is completed at t=t2, and the voltage of the drive winding coil SEC5 becomes zero. Because of the Zener diode Z1 The reverse current is reversed in the gate of the flywheel rectifier switch sl. At this time, although the leakage current flows from the Zener diode to the positive pole of the Zener diode, the magnitude and magnitude of the leakage current Compared with the switching period used, it is negligible. Therefore, the gate charge in the flywheel rectifier switch sl〇 is almost constant, so the far-wheel rectifier switch Si〇 is continuously turned on during this static time ((jeacj time) Here, it is necessary to point out the difference between the present invention and the one shown in the third figure (B) of the prior art. In the circuit of the present invention, the voltage Vgs(S10) of the flywheel rectifier switch S10 will be in this flywheel time period. Maintaining a level of approximately VSEC5, and in the third diagram (B), the voltage level of the voltage Vgs (S7) of the flywheel rectifier switch S7 is maintained at approximately Vsec3 + v〇ffs for a corresponding period of time. At t==t0', the main switch S8 is turned off again. The negative voltage of the negative terminal of the drive winding SEC5 is connected to the negative voltage of 9 1294716, which is good enough to cause the Zener diode Zener to collapse, and g ( 1〇) will stop again at a negative voltage Precisely, the flywheel (Freewheeiing) rectifier switch S10 is turned off. Then, a new switching cycle is started. It is also necessary to point out that in the present invention, the mechanism used by the drifting wheel rectification __ is collapsed by the lion's pole surface. Characteristic, and in the second figure (B), the gate of the flywheel rectifier switch is placed at a lower voltage than the DC compensation by a higher negative bias than the DC compensation. The mechanism of the rectifier switch. - The present invention can be used in many kinds of circuit architectures, and can be used in many aspects, such as the fifth picture display; not in a two-switch (Two Switch), when the main switch S8, S1 is forward converter, phase The principle of circuit operation shown in the fourth® is the same as that of the self-driven synchronous rectifier circuit. In addition, the sixth figure shows a phase shift (Phase Shifted) and a current doubler (Current Doublet) # full bridge (pull bridge), the line architecture is implemented, using the t-autonomous self-driving step rectification of the present invention line. The operating principle of a full-bridge DC-to-DC converter circuit architecture with a phase-twisting and current multiplier can be found in the 1997-1987 edition of a fuel-powered power supply sniper research report page to page A3_25. 〃本, f f 瞒 先 有 有 , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , The reverse polarity is retained to retain the closed-pole charge without the need to add an expensive auxiliary M-switch Sal as shown in the second figure (8). At the same time, when the flywheel (four) ★ coffee rectifier switch S10 is turned off, the present invention will cause ion collapse of the Zener diode to be compared with the second remedy using a Dc surface. The difference in the number of parts used by the present invention in accordance with this principle of operation is much less than that of the second remedy. The present invention does not require the addition of a bias resistor Rbs and a capacitor having a sufficiently high forward DC bias source (possibly costly) and as shown in the aforementioned Figure 682, as shown in the third diagram (B). Czd. As described above, the self-driving synchronous rectification gate driving circuit of the present invention overcomes the η 9§ ' of the body diode in the dead time flywheel (Freewheeling) current switch, and presents the invention patent according to law. The application of the preferred embodiment of the present invention is not limited thereto, and is similar to the structure of the present invention, and is also equipped with 1294716, features, and the like. Or the same as the scope of the invention and the scope of the patent application

11 1294716 [Simple description of the diagram] The first figure (A) is equipped with a self-driven synchronous rectifier line forward converter. The first figure (B) is a waveform time diagram of the prior art forward converter of the first figure (A). The second picture (4) is the pre-June converter of the 637 patent. The first figure (B) is a waveform time diagram of the prior art forward converter of the second figure (A). The third figure (A) is a prior art forward converter of the Japanese Patent No. 882. The third diagram (B) is another embodiment of the prior art listed in the '682 patent. The fourth _) shows an equivalent diagram of the forward converter self-driving synchronous rectification circuit system of the present invention. The fourth graph (B) shows the waveform time chart of the converter shown in the fourth graph (A). The fifth figure shows a diagram of the implementation of the dual switch forward converter in the present invention. The sixth figure shows the phase transition and current multiplier full bridge in the present invention. [Main component symbol description]. king. Converter diagram.

Co, Cl, C2, Czd, C3..... capacitor

Lf, U, L2, L3 · · · · Inductance Pr..... Primary winding coil R, Rgate, Rgatel, Rgate2, Rgate3, Rgate4 · · · _ _ •• Gate resistor

Rbs.....bias resistor

Ro, IU, R2, R3.....load resistors 51, s4, S9.....forward rectifier switches 52, S5, S7, S10, S14.....Flywheel rectifier switches SEC, SEC1, SEC2 , SEC.....Secondary winding coil SEC3, SEC5, SEC6.....drive winding coil S, S6, S8, S11, S12, S13..... main switch

Sal.....Auxiliary MOSFET Switch T · · · · · Transformer Z1 > Z2 > ZD01 > Zene.....Junner Diode D.....Diode D2.... Power Diode 12

Claims (1)

1294716 X. Patent application scope: 1. A "self-driven synchronous rectifier gate drive circuit" includes at least: off, - secondary winding line and - secondary winding line ® convert the input voltage into the output voltage. The secondary winding coil correction can also include a drive coil that is similar to the intermediate tap capability; 1 to the trim (8) and - flywheel (Freewheeling) rectification (four) off connection _ secondary winding coil for rectifying the output, and - gate drive The line includes: 曰 纳 _ _ polar body 'coupled to the secondary drive winding coil of the Wei device, the material can be provided - a kind of 卩 鹤 鹤 讯 制 飞 飞 飞 整流 整流 整流 ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; The gate connector of the freewheeling rectifier switch can be adjusted or expanded (4). The transition time of the flywheel button is controlled by the conduction state in the non-conducting state. 2. For example, the self-driven synchronous rectifier gate drive circuit described in claim 1 of the patent scope, wherein the respective rectifier switch and the freewheeling rectifier are open-circuited as MOSFET switchers. 3. The self-driven synchronous rectifier gate drive circuit of claim 1, wherein the forward rectifier switch stage and the flywheel rectifier switch stage are interconnected and connected to a drive winding coil. The positive terminal is connected, and the negative terminal of the driving winding is connected to the positive electrode of the second phase. 4. The self-driving synchronous rectifier gate drive circuit of claim 3, wherein the positive terminal line of the drive winding coil and the positive terminal line of the primary winding coil have the same polarity. 5. The self-driving synchronous rectifier gate driving circuit according to claim 1, wherein the main function of the two-pole system is to maintain the flywheel during the dead time. By the gate charge of the rectifier switch, during the time interval from the dead time to the time when the primary side switch is turned on, the operating principle for turning off the flywheel rectifier switch is The Jenus diode was completed and collapsed. 6. The self-driving synchronous rectifier gate drive circuit of claim 5, wherein the crash mode of operation in the arrester diode applies a sufficient voltage of 13; 1294716 by the drive winding coil. Caused by. 7. The self-driven synchronous rectifier gate drive circuit described in claim 1 is wherein the forward turn is difficult to advance by the double-face forward conversion ride. 8. - "Self-driving synchronous rectifier gate drive circuit" depends on - the full bridge circuit architecture contains at least: has four main switches, - a secondary winding and a secondary winding coil to convert the input voltage into Output voltage transformer; - Freewheding rectifier open level and second flywheel rectifier switch thief The corresponding connector of the secondary winding coil is connected to rectify the output voltage; and the two interpole driving circuits are respectively included, respectively: - an inductive diode 'coupled to the secondary drive winding of the transformer, providing a drive signal to each of the corresponding flywheel (Freewheeling) rectifier switch gates; and 妓 + Ϊ blocking connected to the respective flywheels (FreeWheeling) Rectifier attack can be sensitive or extended for each job, m 卩 scale · g transition to the material transit state transition time. == Apply for the self-driven synchronous rectifier questioner drive circuit described in item 8 of the patent scope, and the freewheeling rectifier open relationship of each of the flywheels is m〇sfet switch. The circuit is composed of a self-driving synchronous rectifier gate drive as described in Item 8 of the T"t, and the outer coil also includes a 'slant tapped tap" composed of a drive winding coil having an intermediate tap. To the ground of the output of the secondary side. The self-driven synchronous rectifiers described in Circuits 2 and 8 have the same polarity. , the positive terminal line of the circle and the self-driven synchronous rectifier gate drive 1 of the positive terminal line circuit of the domain 2, the Iltt range, and the phase shift of the full bridge circuit structure Turn to the full bridge line. Circuit, basin 2 _ Γ exhausted the self-driven synchronous rectifier gate drive described in item 8 / 4 i on the line is a current multiplier _ 〇 circuit, turn the self-driven synchronous rectification of the eighth item The pole drive system is mainly implemented to maintain the gate charge of the flywheel 14 1294716 (Freewheeling) rectifier switch in the static time (4) (4), and the operation principle for turning off the flywheel rectifier switch is The Jenus diode collapse is complete. 1. The self-driving synchronous rectifier gate driving circuit of claim 14, wherein the crash mode of operation in the arrester diode is caused by applying a sufficient negative voltage to the drive winding coil. . 15 Ί294716 VII. Designated representative map: (1) The representative representative of the case is: Figure 4 (A). (2) A brief description of the component symbols of this representative figure: C3..........capacitor L3..........output inductor Pri..........primary winding Coil R3..........Load resistor S9..........Forward rectifier switch S10..........Flywheel rectifier switch SEC4.........Secondary winding coil SEC5.........Drive winding coil S8..........Main switch T........• • Transformer Z1..........Shenzhen diode R.....gate resistance (gate drive circuit) 8. If there is a chemical formula in this case, please reveal the best Chemical formula showing the characteristics of the invention: