Rectifier bridge device based on ideal diode

Abstract

The invention relates to the technical field of rectifier bridges, in particular to an ultralow-loss rectifier bridge device. A circuit comprises a power supply AC1, a power supply AC2, two groups of high-end driving switches with the same structure and two groups of low-end driving switches with the same structure, the high-end driving switch comprises a transistor V1 and a transistor V4, the low-end driving switch comprises a transistor V2 and a transistor V3, the transistor V1 and the transistor V3 are connected with a power supply AC1, and the transistor V4 and the transistor V2 are connected with a power supply AC2; the high-end driving switches are two groups of PMOS (P-channel Metal Oxide Semiconductor) type high-end ideal diodes and PNP type high-end ideal diodes with the same structure, and the low-end driving switches are two groups of NMOS (N-channel Metal Oxide Semiconductor) type low-end ideal diodes and NPN type low-end ideal diodes with the same structure. The rectifier bridge circuit has the advantages that alternating-current and direct-current power supply simulation tests show that the conduction voltage drop of more than ten rectifier bridge circuits is very small and is far lower than the conduction voltage drop VF of a diode, the loss current is small, and the loss is very low. The combinational logic control circuit has the advantages of simple circuit, high practicability and low cost.

Description

Technical Field

[0001] The present invention relates to the technical field of rectifier bridges, and in particular to a rectifier bridge device based on ideal diodes. Background Art

[0002] Electronic circuits and devices generally require a stable DC power supply. A rectifier (bridge rectifier) ​​is a device that converts AC power to DC. Generally, AC power supplies require rectification, filtering, and conversion to DC before voltage conversion. The following are some of the most commonly used rectification schemes.

[0003] Ordinary diode solution: Due to its unidirectional conductivity, the diode is a natural Oring circuit. The most basic Oring circuit is to add a diode at the output end. Currently, rectifier bridges are mostly implemented using rectifier diodes and filter (energy storage) capacitors. Half-wave rectifier bridges are often used to convert AC power into DC power. It is very simple to implement, but it wastes half a cycle of AC power. The utilization efficiency is about 50%, and the output voltage ripple is relatively large and the efficiency is low. The full-wave bridge rectifier composed of four rectifier diodes makes full use of the entire cycle of AC power. It is a circuit that rectifies the entire cycle of AC power and makes full use of the positive and negative half cycles of AC power. The conversion efficiency is greatly improved compared to half-wave rectification, and the utilization efficiency is close to 100%. There is a filter capacitor at the output end. After passing through the filter capacitor, the output voltage ripple amplitude is very small, and the output voltage is relatively smooth and stable. The rectifier diode conduction voltage drop V F =0.7V~2V (the greater the on-state current, the greater the voltage drop). The on-state voltage drop increases with the increase of input current. For example, the on-state current of rectifier diode S3MC is 0.1A, 1A, 10A, and 20A, and the corresponding voltage drops are 0.74V, 0.85V, 1.16V, and 1.45V, respectively, and the losses are 0.074W, 0.85W, 11.6W, and 29W, respectively. This means that the greater the current, the greater the loss. There is a higher voltage drop on the full-wave rectifier, which is the sum of the two diodes in series: about 2×V F The availability of inexpensive diodes has led to the widespread use of half-wave and full-wave rectifiers in some common circuits.

[0004] Schottky diode solution: Replacing rectifier diodes with Schottky diodes can reduce the forward voltage drop. Taking the Schottky diode SS54 as an example, the voltage drops corresponding to currents of 0.1A, 1A, 10A, and 20A are 0.3V, 0.4V, 0.85V, and 1.4V, respectively, and the losses are 0.03W, 0.4W, 8.5W, and 28W, respectively. As the current increases, the losses of the Schottky diode and the rectifier diode decrease. Replacing rectifier diodes with Schottky diodes can reduce the forward voltage drop and improve conversion efficiency and energy utilization. However, the Schottky diode has a large reverse current, low withstand voltage, and high cost, which limits its application range. The voltage drop of a full-wave rectifier bridge is the sum of two Schottky diodes in series: approximately 2×V F .

[0005] MOS tube solution: The MOS tube rectifier bridge in the two patents "POE rectifier bridge device based on MOS power tube, patent number: CN201820137186.9" and "A rectifier bridge device and rectifier device based on field effect tube, patent number: CN202222604210.4" is composed of two PMOS tubes and two NMOS tubes, which are mutually controlled (without additional MOS tube devices). The conduction voltage drop of the MOS tube is very small, and the voltage waveform (unfiltered) passing through the rectifier bridge is very good-looking, which is basically the same as its input voltage waveform, and is similar to an ordinary rectifier bridge. However, the filtering effect of loading the filter capacitor is very poor. When the author used Multisim software to simulate, the effect of using the filter capacitor was the same as that of not using the filter capacitor. Increasing the resistance of the load resistor or the capacity of the filter capacitor did not help. Specifically, the voltage of the filter capacitor was discharged and charged quickly (the rising waveform of the filter capacitor voltage means charging, and the falling waveform means discharging). The output voltage was not as smooth and stable as the rectifier bridge composed of diodes. After multiple simulation tests by the author, it was verified that there was a backflow (reverse) current in the drain-source channels of the two PMOS tubes. This is because the PMOS tube is still in the on state outside the conduction angle and a reverse current occurs (theoretically it should be in the off state); similarly, there is a backflow current when the two NMOS tubes at the low end are alternately turned on. This is why the filtering effect is very poor. Therefore, the circuit needs to be changed in design, such as using a charge pump to boost the gate of the PMOS tube to control it.

[0006] The MOS tube solution only uses 2 NMOS tubes + 2 PMOS tubes to replace 4 rectifier diodes. Although it solves the disadvantage of the large voltage drop caused by the diode, it does not have the function of curbing the backflow (reverse) current. When the output voltage is higher than the input voltage, due to the absence of the rectifier diode, the drain-source channel impedance of the MOS tube is lower, and a large amount of current will flow back from the output to the input, and only a small amount of current will flow to the load. The discharge speed of the filter capacitor is significantly accelerated, and the output voltage also drops rapidly. The size is basically the same as the input voltage, and the MOS tube rectifier bridge will also lose its meaning.

[0007] Existing diode-based rectification solutions all have certain shortcomings: pure diode rectifier bridges suffer from high voltage drops, and pure MOS tube rectifier bridges can suffer from backflow current. Existing patents (an ultra-low-loss ideal diode, patent number: CN201821304820.X) pertain to high-end ideal diode circuits; (an ultra-low-loss low-end ideal diode, patent number: CN202020206261.X) pertain to low-end ideal diodes, both of which exhibit unidirectional conductivity. The high-end ideal diode acts as a high-side drive switch, installed between the positive pole of the power supply and the load. The high-side drive switch controls whether the power supply is turned on or off, allowing current to "flow out" to the load circuit. The low-side ideal diode, on the other hand, acts as a low-side drive switch, installed between the load and the negative pole of the power supply, controlling whether the negative pole is turned on or off, thereby "sinking" current from the load.

[0008] Combining the unidirectional conductive characteristics of the above-mentioned high-end ideal diode and low-end ideal diode, it is necessary to develop an ultra-low loss rectifier bridge device based on high-end ideal diode and low-end ideal diode to complement each other's advantages. Summary of the Invention

[0009] The technical problem to be solved by the present invention is to overcome the deficiencies in the prior art and provide a rectifier bridge device composed of a high-end ideal diode and a low-end ideal diode.

[0010] To solve the above technical problems, the present invention provides a technical solution: a rectifier bridge device based on an ideal diode, comprising a circuit, wherein the circuit includes a power supply AC1, a power supply AC2, two groups of high-side drive switches with the same structure, and two groups of low-side drive switches with the same structure;

[0011] The high-side drive switch includes transistors V1 and V4, and the low-side drive switch includes transistors V2 and V3. The transistors V1 and V3 are connected to the power supply AC1, and the transistors V4 and V2 are connected to the power supply AC2.

[0012] The high-end drive switches are two groups of PMOS high-end ideal diodes and PNP high-end ideal diodes with the same structure, and the low-end drive switches are two groups of NMOS low-end ideal diodes and NPN low-end ideal diodes with the same structure.

[0013] Preferably, the PMOS type high-end ideal diode includes a PMOS main tube and PMOS auxiliary tubes A and B;

[0014] The source of the PMOS auxiliary tube A is connected to the drain of the PMOS main tube, the drain is grounded through a resistor RA, and the gate and the drain are short-circuited;

[0015] The source of the PMOS auxiliary tube B is connected to the source of the PMOS main tube, the drain is grounded through the resistor RB, the gate is connected to the gate of the PMOS auxiliary tube A, and the gate of the PMOS main tube is connected to the drain of the PMOS auxiliary tube B.

[0016] Preferably, the PNP type high-end ideal diode includes a PMOS main tube and a PNP pair of tubes A and B;

[0017] The emitter of the PNP transistor A is connected to the drain of the PMOS transistor, the collector is grounded via a resistor RA, and the base and collector are short-circuited;

[0018] The emitter of the PNP transistor B is connected to the source of the PMOS transistor, the collector is grounded through the resistor RB, the base is connected to the base of the PNP transistor A, and the collector is also connected to the gate of the PMOS transistor.

[0019] Preferably, the NMOS type low-end ideal diode includes an NMOS main tube and NMOS auxiliary tubes A and B;

[0020] The source of the NMOS auxiliary tube A is connected to the drain of the NMOS main tube, the drain is connected to the resistor RA, the gate and the drain are short-circuited, and the gate is connected to the gate of the NMOS auxiliary tube B;

[0021] The source of the NMOS auxiliary tube B is connected to the source of the NMOS main tube, the drain is connected to the resistor RB, and the drain is also connected to the gate of the NMOS main tube.

[0022] Preferably, the NPN type low-end ideal diode includes an NMOS main tube and an NPN pair of tubes A and B;

[0023] The emitter of the NPN transistor A is connected to the drain of the NMOS transistor, the collector is connected to the resistor RA, and the collector and the base are short-circuited;

[0024] The emitter of the NPN tube B is connected to the source of the NMOS tube, the collector is connected to the resistor RB, and the base is connected to the gate of the NMOS tube.

[0025] The advantages of the present invention over the prior art are: A rectifier bridge device composed of multiple high-end and low-end ideal diodes provides backflow protection, protecting the preceding circuit. The PMOS and NMOS transistors have low on-resistance, low conduction loss, and are widely applicable. The combinational logic control circuit is simple and highly practical. For high-power power supply control, the PMOS and NMOS transistors can be selected with an on-resistance of several milliohms between the drain and source, allowing for high current flow. The voltage drop across the PMOS and NMOS transistors is minimal, allowing them to approximate an ideal diode. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is the schematic diagram of a rectifier bridge device composed of common diodes;

[0027] Figure 2 This is a schematic diagram of a rectifier bridge device based on a PMOS high-end ideal diode and an NMOS low-end ideal diode according to the present invention;

[0028] Figure 3 This is a schematic diagram of a rectifier bridge device based on a PNP-type high-end ideal diode and an NPN-type low-end ideal diode according to the present invention;

[0029] Figure 4 This is a schematic diagram of a rectifier bridge device based on a PMOS high-end ideal diode and an NPN low-end ideal diode according to the present invention;

[0030] Figure 5 This is a schematic diagram of a rectifier bridge device based on a PNP-type high-end ideal diode and an NMOS-type low-end ideal diode according to the present invention;

[0031] Figure 6 yes Figure 2 Circuit AC power supply simulation test diagram;

[0032] Figure 7 yes Figure 2 Circuit DC power supply simulation test diagram;

[0033] Figure 8 yes Figure 3 Circuit AC power supply simulation test diagram;

[0034] Figure 9 yes Figure 3 Circuit DC power supply simulation test diagram. DETAILED DESCRIPTION

[0035] The present invention will be described in further detail below with reference to the accompanying drawings.

[0036] Technical solution 1: A rectifier bridge device composed of a PMOS high-end ideal diode and an NMOS low-end ideal diode.

[0037] The prior art patent (an ultra-low-loss ideal diode, patent number: CN201821304820.X) is a high-end ideal diode, including a logic control circuit and a PMOS transistor. The logic control circuit is composed of two independent auxiliary PMOS transistors or a PMOS pair with identical parameters and packaged together, and two resistors R1 and R2 to form a comparator circuit to control the conduction and cutoff of the PMOS transistor: when the input voltage is not less than the output voltage, the PMOS transistor is turned on; otherwise, the PMOS transistor is cut off, preventing the output current from flowing back to the input terminal and protecting the input power circuit, which is equivalent to a high-end ideal diode. Because the PMOS transistor is a voltage device, the PMOS transistor conduction voltage drop and bias current are very small (in the microampere level), and the loss is negligible. Compared with the rectifier bridge composed of traditional diodes, the loss is significantly reduced.

[0038] The existing patent (an ultra-low-loss low-end ideal diode, patent number: CN202020206261.X) uses an NMOS transistor as the low-end ideal diode of the main circuit. The logic control circuit consists of two NMOS transistors of the same model or a NMOS pair with the same parameters, packaged together, and two resistors R1 and R2. This circuit controls the conduction and cutoff of the NMOS transistor: when the source voltage of the NMOS transistor is greater than the negative power supply voltage (NMOS transistor drain), the NMOS transistor conducts; when the source voltage of the NMOS transistor is less than the negative power supply voltage, the NMOS transistor is cut off, preventing current from flowing back through the NMOS transistor to the source of the NMOS transistor, thereby protecting the NMOS transistor source load circuit. This circuit provides protection against reverse connection when the positive power supply VCC and the negative power supply GND are connected incorrectly.

[0039] NMOS transistors use electrons as "majority carriers," and electrons have higher mobility than holes, the "majority carriers" of PMOS transistors. At the same physical density, NMOS transistors have higher transconductance and lower on-resistance than PMOS transistors. The on-resistance of NMOS transistors is generally 1 / 3 to 1 / 2 that of PMOS transistors of the same size. For the same on-resistance, NMOS transistors generally require less silicon wafers, resulting in lower gate capacitance and threshold voltage than PMOS transistors. However, due to the higher on-resistance of PMOS transistors, their higher price, slower speed, and limited replacement options, NMOS transistors are still commonly used in low-end switch drivers.

[0040] The schematic diagram of the rectifier bridge device composed of common diodes is as follows Figure 1As shown in the figure: Although the four diodes have the same model, their functions are different due to their different positions: diodes V1 and V4 are equivalent to high-side diodes, and V2 and V3 are equivalent to low-side diodes. According to the unidirectional conductivity characteristics of high-side ideal diodes and low-side ideal diodes, diodes V1 and V4 are replaced by two high-side ideal diodes, and diodes V2 and V3 are replaced by two low-side ideal diodes. The rectifier bridge device composed of high-side ideal diodes based on PMOS tubes (referred to as PMOS high-side ideal diodes) and low-side ideal diodes based on NMOS tubes (referred to as NMOS low-side ideal diodes) is as shown in the figure. Figure 2 shown.

[0041] Technical solution 2: A rectifier bridge device composed of a PNP high-end ideal diode and an NPN low-end ideal diode.

[0042] Similar to Technical Solution 1, a MOS transistor has three electrodes: gate (G), source (S), and drain (D), corresponding to the base (B), emitter (E), and collector (C) of a bipolar junction transistor: gate to base (G→B), source to emitter (S→E), and drain to collector (D→C). The bias circuit for an enhancement-mode MOS transistor is essentially the same as that for a bipolar junction transistor. In some switching situations, they can be used interchangeably. NPN and NMOS transistors are interchangeable, requiring only slightly different bias circuits. As long as the bias circuit is properly configured, they can operate equally well, though their losses are higher than those of NMOS transistors. Similarly, PNP and PMOS transistors are interchangeable. Based on the above replacement ideas, on the basis of technical solution 1, NPN tubes can be used to replace NMOS auxiliary tubes, and PNP tubes can be used to replace PMOS auxiliary tubes, to obtain a rectifier bridge device composed of a high-end ideal diode composed of PMOS main tube + PNP pair tubes (referred to as PNP type high-end ideal diode) and a low-end ideal diode composed of NMOS main tube + NPN pair tubes (referred to as NPN type low-end ideal diode), such as Figure 3 shown.

[0043] Technical Solution 3: Based on the ideas of the above-mentioned Technical Solution 1 and Technical Solution 2, a combination design idea can be adopted for the high-end ideal diode and the low-end ideal diode. The NMOS low-end ideal diode of the embodiment 1 is replaced by an NPN low-end ideal diode to obtain a rectifier bridge device composed of a PMOS high-end ideal diode and an NPN low-end ideal diode, such as Figure 4 As shown; the analysis process refers to Technical Solution 1.

[0044] Technical Solution 4: Similar to Technical Solution 3, a PNP type high-end ideal diode is used to replace the PMOS type high-end ideal diode in Implementation Method 1, thereby obtaining a rectifier bridge device composed of a PNP type high-end ideal diode + an NMOS type low-end ideal diode. Figure 5 As shown, the analysis process refers to Technical Solution 2.

[0045] From the above, we can know that: PMOS type high-end ideal diode, PNP type high-end ideal diode, NMOS type low-end ideal diode, NPN type low-end ideal diode are combined and designed. Replace with PMOS type high-end ideal diode or PNP type high-end ideal diode Figure 1 Diode V1 or V2; NMOS type low-end ideal diode or NPN type low-end ideal diode replacement Figure 1 The diode V3 or V4 in the middle; the four ideal diodes are independent of each other, and there are a total of sixteen technical solutions for their combination. The combination forms are shown in Table 1. Technical solutions (5) to (16) can refer to technical solutions (1) to (4) and are not described in detail one by one.

[0046] Table 1 Combination of technical solutions

[0047]

[0048]

[0049] Implementation Method 1

[0050] A rectifier bridge device consisting of a high-end ideal diode of a PMOS tube and a low-end ideal diode of an NMOS tube.

[0051] The prior art patent (an ultra-low-loss ideal diode, patent number: CN201821304820.X) is a high-end ideal diode, including a logic control circuit and a PMOS transistor. The logic control circuit consists of two independent auxiliary PMOS transistors or a PMOS pair with identical parameters packaged together, and two resistors R1 and R2 forming a comparator circuit to control the conduction and cutoff of the PMOS transistor: when the input voltage is not less than the output voltage, the PMOS transistor is turned on; otherwise, the PMOS transistor is turned off, preventing the output current from flowing back to the input terminal and protecting the input power circuit, which is equivalent to a high-end ideal diode. Because the PMOS transistor is a voltage device, the PMOS transistor conduction voltage drop and bias current are very small (microampere level), and the loss is negligible. Compared with the rectifier bridge composed of traditional diodes, the loss is significantly reduced.

[0052] The existing patent (an ultra-low-loss low-end ideal diode, patent number: CN202020206261.X) uses an NMOS transistor as the low-end ideal diode of the main circuit. The logic control circuit consists of two NMOS transistors of the same model or a NMOS pair with the same parameters, packaged together, and two resistors R1 and R2. This circuit controls the conduction and cutoff of the NMOS transistor: when the source voltage of the NMOS transistor is greater than the negative power supply voltage (NMOS transistor drain), the NMOS transistor conducts; when the source voltage of the NMOS transistor is less than the negative power supply voltage, the NMOS transistor is cut off, preventing current from flowing back through the NMOS transistor to the source of the NMOS transistor, thereby protecting the NMOS transistor source load circuit. This circuit provides protection against reverse connection when the positive power supply VCC and the negative power supply GND are connected incorrectly.

[0053] NMOS transistors use electrons as "majority carriers," and electrons have higher mobility than holes, the "majority carriers" of PMOS transistors. At the same physical density, NMOS transistors have higher transconductance and lower on-resistance than PMOS transistors. The on-resistance of NMOS transistors is generally 1 / 3 to 1 / 2 that of PMOS transistors of the same size. For the same on-resistance, NMOS transistors generally require less silicon wafers, resulting in lower gate capacitance and threshold voltage than PMOS transistors. However, due to the higher on-resistance of PMOS transistors, their higher price, slower speed, and limited replacement options, NMOS transistors are still commonly used in low-end drives.

[0054] Figure 1 The schematic diagram of the rectifier bridge device composed of common diodes: diodes V1 and V4 are equivalent to high-end diodes, and V2 and V3 are equivalent to low-end diodes. According to the unidirectional conductive characteristics of high-end ideal diodes and low-end ideal diodes, two high-end ideal diodes are used to replace Figure 1 Diodes V1 and V4 in the circuit are replaced with two low-side ideal diodes. Figure 1 The diodes V2 and V3 in the circuit are used to obtain a rectifier bridge device composed of a PMOS type high-end ideal diode and an NMOS type low-end ideal diode. Figure 2 As shown,

[0055] Among them, the PMOS auxiliary tubes V1A, V1B, V4A, and V4B can be the same model as the PMOS power-type main tubes V1 and V4, or they can be ordinary small-signal PMOS tubes; the NMOS auxiliary tubes V2A, V2B, V3A, and V3B can be the same model as the NMOS power-type main tubes V2 and V3, or they can be ordinary small-signal NMOS tubes; the eight bias resistors R1A, R1B, R2A, R2B, R3A, R3B, R4A, and R4B have the same resistance value, and the resistance value depends on the specific application scenario.

[0056] Figure 2The theoretical analysis of the rectifier bridge device is as follows: When the AC power supply AC1 is in the positive half cycle, when V1 GS =V1G-Vout=GND-Vout=0V-(AC1-V F )=V F -AC1<V TP When (V F is the conduction voltage drop of the MOS tube body diode, V TP is the conduction threshold voltage of PMOS tubes V1 and V4), the gate of PMOS tube V1 is low level and the source is high level, the drain-source channel is turned on; when V2 GS =Vout-GND=(AC1-V F )-0V=AC1-V F >V TN When (V TN (where ) is the turn-on threshold voltage of the NMOS transistors V2 and V3. The gate of the NMOS transistor V2 is at a high level and the source is at a low level, and the drain-source channel is turned on. The PMOS transistor V4 and the NMOS transistor V3 are both cut off. The current conduction path is the transformer secondary positive terminal AC1 → PMOS transistor V1 → Vout → load RL → GND → NMOS transistor V2 → transformer secondary negative terminal AC2.

[0057] When AC power supply AC2 is in the positive half cycle, when V4 GS =V4G-Vout=GND-Vout=0V-(AC2-V F )=V F -AC2<V TP , the gate of PMOS tube V4 is low level, the source is high level, and the drain-source channel is turned on; when V3 GS =Vout-GND=(AC2-V F )-0V=AC2-V F >V TN When the gate of NMOS transistor V3 is high and the source is low, the drain-source channel is turned on; PMOS transistors V1 and NMOS transistors V2 are both turned off. The current conduction path is from the transformer secondary positive terminal AC2 to PMOS transistor V4 to Vout to the load RL to GND to NMOS transistor V3 to the transformer secondary negative terminal AC1. MOS transistors with low conduction threshold voltage are preferred for better rectification.

[0058] Implementation Method 2

[0059] A rectifier bridge device consisting of a PNP type (PMOS main tube + PNP tube pair) high-end ideal diode and an NPN type (NMOS main tube + NPN tube pair) low-end ideal diode.

[0060] Similar to Technical Solution 1, the three electrodes of a MOS transistor—gate (G), source (S), and drain (D)—correspond to the base (B), emitter (E), and collector (C) of a bipolar junction transistor, respectively: gate to base (G→B), source to emitter (S→E), and drain to collector (D→C). The bias circuit for an enhancement-mode MOS transistor is essentially the same as that for a bipolar junction transistor, and they can be used interchangeably in some switching situations. NPN transistors and NMOS transistors are interchangeable, requiring only a slight difference in the bias circuit. As long as the bias circuit is properly configured, they can operate equally well, though their losses are higher than those of NMOS transistors. Similarly, PNP transistors and PMOS transistors are interchangeable. Based on the above replacement ideas, on the basis of technical solution 1, NPN tubes can be used to replace NMOS auxiliary tubes, and PNP tubes can be used to replace PMOS auxiliary tubes, to obtain a rectifier bridge device composed of a PNP type high-end ideal diode composed of a PMOS main tube + a PNP pair of tubes, and an NPN type low-end ideal diode composed of an NMOS main tube + an NPN pair of tubes, as shown in FIG. Figure 3 As shown, the PNP auxiliary tubes V1A, V1B, V4A, and V4B can be selected as power type or ordinary small signal type PNP tubes; the NPN auxiliary tubes V2A, V2B, V3A, and V3B can be selected as power type or ordinary small signal type NPN tubes; the eight bias resistors R1A, R1B, R2A, R2B, R3A, R3B, R4A, and R4B have the same resistance value. Since NPN and PNP are current type devices, in order to ensure reliability, the bias resistor value should be smaller than that of technical solution one.

[0061] The theoretical analysis of the rectifier bridge device of the second embodiment refers to the first embodiment.

[0062] Implementation Method 3

[0063] According to the ideas of the above technical solutions 1 and 2, a combined design idea can be adopted for the high-end ideal diode and the low-end ideal diode. The NMOS low-end ideal diode of the first embodiment is replaced by an NPN low-end ideal diode, and the schematic diagram of the rectifier bridge device composed of a PMOS high-end ideal diode and an NPN low-end ideal diode is obtained. Figure 4 shown.

[0064] Implementation Method 4

[0065] The PNP type high-end ideal diode is used to replace the PMOS type high-end ideal diode in the first embodiment, and the schematic diagram of the rectifier bridge device composed of the PNP type high-end ideal diode and the NMOS type low-end ideal diode is obtained. Figure 5 shown.

[0066] Implementation method 3 and implementation method 4 corresponding to technical solution 3 and technical solution 4 are omitted. The theoretical analysis of the rectifier bridge devices of the two methods refers to implementation method 1 and implementation method 2.

[0067] according to Figure 2 、 Figure 3 The schematic diagram was simulated using National Instruments' Multisim (version V14.0) software. The PMOS tube used was ON Semiconductor's NVTFS5124PLTAG, with a minimum on-threshold voltage of V TP(MIN) =-1.5V, maximum V TP(MAX) =-2.5V, typical value V not given TP , the on-state current can reach -6A, the on-state resistance R DS(ON) =0.26Ω(V GS =-10V), R DS(ON) =0.38Ω(V GS =-4.5V). The NMOS tube is made by NXP, model BSP030, with a minimum on-threshold voltage of V TN(MIN) =1V, maximum value V TN(MAX) =2.8V, typical value V is not given TN , the conduction current is up to 10A, the conduction resistance R DS(ON) =30mΩ(V GS =10V), R DS(ON) =50mΩ(V GS =4.5V), the specific simulation test is as follows.

[0068] Implementation Method 1 Simulation

[0069] Figure 2 The turns ratio of the primary and secondary coils of the transformer in the circuit shown is 10:1, the load impedance is 100Ω, the filter capacitor is 1000μF, and the resistance of the eight bias resistors are all 100kΩ. The AC power supply simulation test is as follows: Figure 6 As shown. Using a four-channel oscilloscope, Channel A (Channel_A) is a 220V AC power supply, Channel B (Channel_B) is the transformer secondary AC1 end, Channel C (Channel_C) is the transformer secondary AC2 end, and Channel D (Channel_D) is the rectified voltage Vout. Figure 6It can be seen that when the maximum voltage of the 220V AC power supply in the positive half cycle is 308.135V, AC1 = 30.809V, the rectified voltage Vout = 30.681V, and the conduction voltage drop is 30.809V-30.681V = 0.128V; when the maximum voltage of the 220V AC power supply in the negative half cycle is -309.715V, AC2 = 30.965V, the rectified voltage Vout = 30.904V, and the conduction voltage difference is 30.965V-30.904V = 0.061V. The conduction voltage drop is very small, much lower than the conduction voltage drop V of the diode. F .

[0070] When the AC power supply AC1 is in the positive half cycle, when AC1-V F >-V TP When the drain-source channel of PMOS tube V1 is turned on; when AC1-V F >V TN When the gate of NMOS tube V2 is high and the source is low, the drain-source channel is turned on; PMOS tube V4 and NMOS tube V3 are both cut off, and no current backflow occurs. When the AC power supply AC2 is in the positive half cycle, when AC2-V F >-V TP , the drain-source channel of PMOS tube V4 is turned on; when AC2-V F >V TN , the drain-source channel of NMOS tube V3 is turned on; PMOS tube V1 and NMOS tube V2 are both turned off, and no current backflow occurs. The voltage waveform after filtering is very smooth and stable, such as Figure 6 Shown as black line (oscilloscope channel D).

[0071] If a 30V DC power supply is connected to the AC1 and AC2 terminals, that is, the AC1 terminal is connected to the positive pole of the 30V power supply and the AC2 terminal is connected to the negative pole of the power supply, the DC power supply simulation test is as follows: Figure 7 As shown, the voltage is measured using an oscilloscope. Figure 7 It can be seen that AC1 = 29.989V, the rectified voltage Vout = 29.914V, the on-state voltage drop of the PMOS tube V1 is 29.989V-29.914V=0.075V, and the corresponding on-state impedance is approximately R DS =250mΩ, which is consistent with the specification. When AC2 is connected to the positive pole of the 30V power supply and AC1 is connected to the negative pole of the power supply, AC2 = 29.989V, the rectified voltage Vout = 29.914V, the PMOS tube V4 conduction voltage drop is 29.989V-29.914V=0.075V, and the NMOS tube V3 conduction voltage drop is 11.052mV. The conduction voltage drop is very small, much lower than the diode conduction voltage drop V F, and no current backflow occurs. The positive output current of the power supply is 300.548mA, the current flowing through the load is 299.138mA, and the bias circuit current loss is approximately 300.548mA-299.138mA=1.410mA. The bias loss P=30V×1.410mA=42.3mW. If the resistance values ​​of all eight bias resistors are changed to 1MΩ, the positive output current of the power supply is 299.276mA, the current flowing through the load is 299.134mA, and the bias circuit current loss is approximately 299.276mA-299.134mA=0.142mA, which is inversely proportional to the bias resistor value. The current loss is very low, and the bias loss P=30V×0.142mA=4.26mW.

[0072] The above simulation tests of AC power supply and DC power supply show that the conduction voltage drop is very small, much lower than the conduction voltage drop of the diode V F , the loss current is mA level, and the loss is very low.

[0073] Implementation Method 2 Simulation

[0074] Figure 3 AC power simulation test such as Figure 8 As shown, the test conditions are the same as those in the first embodiment: Figure 8 It can be seen that when the maximum voltage of the 220V AC power supply in the positive half cycle is 309.583V, AC1 = 30.935V, the rectified voltage Vout = 30.581V, and the voltage difference is 30.935V-30.581V=0.372V; when the maximum voltage of the 220V AC power supply in the negative half cycle is -309.090V, AC2 = 30.886V, the rectified voltage Vout = 30.536V, and the conduction voltage drop is 30.886V-30.536V=0.350V, which is less than the conduction voltage drop V of the diode. F .

[0075] If a 30V DC power supply is used and connected to the positive terminal AC1 and the negative terminal AC2, that is, AC1 is connected to the positive pole of the 30V power supply and AC2 is connected to the negative pole of the power supply, the DC power supply simulation test is as follows: Figure 9 As shown, the voltage is measured using an oscilloscope. Figure 9 It can be seen that AC1=29.988V, rectified voltage Vout=29.913V, and the on-state voltage drop of PMOS tube V1 is 29.988V-29.913V=0.075V. The corresponding on-state impedance is approximately R DS =250mΩ, which is consistent with the specification. The NMOS tube V2 conduction voltage drop is 11.659mV. When AC2 is connected to the positive pole of the 30V power supply and AC1 is connected to the negative pole of the power supply, the conduction voltage difference is still 29.988V-29.913V=0.075V. The conduction voltage drop is very small, much lower than the conduction voltage drop of the diode V F, and no current backflow occurs. The positive output current of the power supply is 301.185mA, and the current flowing through the load is 299.127mA. The bias circuit current loss is approximately 301.185mA - 299.127mA = 2.058mA. The bias loss P = 30V × 2.058mA = 61.74mW, which is slightly higher than the first embodiment.

[0076] Comparison of DC power supply simulations for Implementation Methods 1 and 2: Under the same power supply and load conditions, the forward voltage drop of the low-end ideal diode NMOS V2 is 11.659mV or 11.052mV, while the forward voltage drop of the high-end ideal diode PMOS V1 is 75mV. The NMOS transistor has the smallest forward voltage drop and lower losses, making the rectifier bridge circuit constructed in Implementation Method 1 the preferred choice.

[0077] The simulation of the third and fourth implementation modes is omitted, and reference will be made to the simulation of the first and second implementation modes.

[0078] The beneficial effects of the present invention are: Compared with the traditional pure diode rectifier bridge, the voltage drop is larger (2×V F ), pure MOS tube rectifier bridge has the problem of backflow current, weighing the pros and cons of diodes and MOS tubes, combining the unidirectional conductivity of diodes and the low on-resistance R of MOS tubes DS Characteristics, leveraging strengths to offset weaknesses and achieve complementary advantages: The above solution uses more than ten types of rectifier bridge devices composed of high-end ideal diodes and low-end ideal diodes, which have the function of preventing backflow and can protect the previous stage circuit. PMOS and NMOS tubes have low on-resistance, low conduction loss, and are widely used. The combinational logic control circuit is simple and practical. For high-power power supply control, PMOS and NMOS tubes can be selected as power tube devices with an on-resistance of several milliohms between the drain and source and large current. The voltage drop across the PMOS and NMOS tubes is very small, and they can be approximated as an ideal diode. MOS tubes have low on-resistance, are cheap, have a wide selection, and have simple circuits and low costs.

[0079] The above describes in detail the preferred embodiments of the present invention. It should be understood that those skilled in the art can make numerous modifications and variations based on the concepts of the present invention without inventive effort. Therefore, any technical solutions that can be derived by those skilled in the art through logical analysis, reasoning, or limited experimentation based on the concepts of the present invention and the prior art should be within the scope of protection defined by the claims.

Claims

1. A rectifier bridge device based on an ideal diode, characterized in that: The circuit includes a power supply AC1, a power supply AC2, two groups of high-side drive switches with the same structure, and two groups of low-side drive switches with the same structure; The high-side drive switch includes transistors V1 and V4, and the low-side drive switch includes transistors V2 and V3. The transistors V1 and V3 are connected to the power supply AC1, and the transistors V4 and V2 are connected to the power supply AC2. The high-end drive switches are two groups of PMOS high-end ideal diodes and PNP high-end ideal diodes with the same structure, and the low-end drive switches are two groups of NMOS low-end ideal diodes and NPN low-end ideal diodes with the same structure.

2. The ideal diode-based rectifier bridge device according to claim 1, wherein: The PMOS type high-end ideal diode includes a PMOS main tube and PMOS auxiliary tubes A and B; The source of the PMOS auxiliary tube A is connected to the drain of the PMOS main tube, the drain is grounded through a resistor RA, and the gate and the drain are short-circuited; The source of the PMOS auxiliary tube B is connected to the source of the PMOS main tube, the drain is grounded through the resistor RB, the gate is connected to the gate of the PMOS auxiliary tube A, and the gate of the PMOS main tube is connected to the drain of the PMOS auxiliary tube B.

3. The ideal diode-based rectifier bridge device according to claim 1, wherein: The PNP type high-end ideal diode includes a PMOS main tube and a PNP pair of tubes A and B; The emitter of the PNP transistor A is connected to the drain of the PMOS transistor, the collector is grounded via a resistor RA, and the base and collector are short-circuited; The emitter of the PNP transistor B is connected to the source of the PMOS transistor, the collector is grounded through the resistor RB, the base is connected to the base of the PNP transistor A, and the collector is also connected to the gate of the PMOS transistor.

4. A rectifier bridge device based on an ideal diode according to claim 2 or 3, characterized in that: The NMOS type low-end ideal diode includes an NMOS main tube and NMOS auxiliary tubes A and B; The source of the NMOS auxiliary tube A is connected to the drain of the NMOS main tube, the drain is connected to the resistor RA, the gate and the drain are short-circuited, and the gate is connected to the gate of the NMOS auxiliary tube B; The source of the NMOS auxiliary tube B is connected to the source of the NMOS main tube, the drain is connected to the resistor RB, and the drain is also connected to the gate of the NMOS main tube.

5. A rectifier bridge device based on an ideal diode according to claim 2 or 3, characterized in that: The NPN low-end ideal diode includes an NMOS main tube and an NPN pair of tubes A and B; The emitter of the NPN transistor A is connected to the drain of the NMOS transistor, the collector is connected to the resistor RA, and the collector and the base are short-circuited; The emitter of the NPN tube B is connected to the source of the NMOS tube, the collector is connected to the resistor RB, and the base is connected to the gate of the NMOS tube.

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