Ideal diode circuit

Abstract

The utility model belongs to the technical field of power supply circuits, and relates to an ideal diode circuit which comprises a PNP type triode Q1, a PMOS type field effect transistor Q2, a PNP type triode Q3, a resistor R1, a resistor R2 and a resistor R3. One end of the resistor R1 is respectively connected with a collector electrode of the PNP type triode Q1, a base electrode of the PNP type triode Q1 and a base electrode of the PNP type triode Q3, an emitting electrode of the PNP type triode Q1 is connected with a drain electrode of the PMOS type field effect transistor Q2, and a source electrode of the PMOS type field effect transistor Q2 is respectively connected with one end of the resistor R3 and an emitting electrode of the PNP type triode Q3. The grid electrode of the PMOS type field effect transistor Q2 is connected with the other end of the resistor R3, the collector electrode of the PNP type triode Q3 and one end of a resistor R2. By using one PMOS transistor and two PNP triodes, the circuit is simple, low in cost and high in reliability, and has the functions of low loss and backflow prevention.

Description

Technical Field

[0001] The utility model relates to the technical field of power supply circuits, and more specifically to an ideal diode circuit. Background Art

[0002] In a redundant power supply system with multiple power supplies, reverse polarity protection is usually required to prevent the output power from flowing back or the on-site input power wiring from being incorrect, which may cause the circuit board to burn out.

[0003] Existing designs use the unidirectional conductivity of Schottky diodes to achieve backflow prevention, but diodes have a large voltage drop, which causes high heat generation and power loss in high-current power supply systems, which is restrictive. Some circuits use dedicated ideal diode control chips, such as TI's LM5051, but the cost is relatively high. There are also solutions built using discrete devices, but the circuit design is relatively complicated. Utility Model Content

[0004] The technical problem to be solved by the utility model is that in the existing multi-power system redundant power supply system, the anti-backflow function is realized by the unidirectional conductivity of the Schottky diode, but the diode generates a large amount of heat and has a high power loss in the high-current power supply system. In view of the above-mentioned defects of the prior art, an ideal diode circuit is provided, including:

[0005] PNP transistor Q1, PMOS field effect transistor Q2, PNP transistor Q3, resistor R1, resistor R2 and resistor R3;

[0006] One end of the resistor R1 is respectively connected to the collector of the PNP transistor Q1, the base of the PNP transistor Q1, and the base of the PNP transistor Q3, the emitter of the PNP transistor Q1 is connected to the drain of the PMOS field effect transistor Q2, the source of the PMOS field effect transistor Q2 is respectively connected to one end of the resistor R3 and the emitter of the PNP transistor Q3, and the gate of the PMOS field effect transistor Q2 is respectively connected to the other end of the resistor R3, the collector of the PNP transistor Q3, and one end of the resistor R2.

[0007] Preferably, the other end of the resistor R1 is grounded.

[0008] Preferably, the other end of the resistor R2 is grounded.

[0009] Preferably, the PNP transistor Q1 and the PNP transistor Q3 are of the same model.

[0010] Preferably, the PMOS field effect transistor Q2 is any one of WPM3407-3, WPM3401-3 and AO3401.

[0011] Preferably, the PNP transistor Q1 and the PNP transistor Q3 are any one of models 9012, 9015, and MMBT3906.

[0012] The implementation of the ideal diode circuit of the utility model has the following beneficial effects: by using a PMOS tube and two PNP transistors, the circuit is simple, the cost is low, the reliability is high, and the function of low loss and backflow prevention is achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the embodiments or the prior art descriptions. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without creative work. The utility model will be further described below in combination with the drawings and embodiments. In the drawings:

[0014] Figure 1 It is a circuit diagram of an ideal diode circuit of the utility model. DETAILED DESCRIPTION

[0015] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0016] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back...), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0017] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the utility model, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the utility model.

[0018] See also Figure 1 , is the circuit diagram of the ideal diode circuit of the utility model. Figure 1 As shown, in the ideal diode circuit provided in the first embodiment of the utility model, at least: PNP transistor Q1, PMOS field effect transistor Q2, PNP transistor Q3, resistor R1, resistor R2 and resistor R3; one end of resistor R1 is connected to the collector of PNP transistor Q1, the base of PNP transistor Q1 and the base of PNP transistor Q3 respectively, the emitter of PNP transistor Q1 is connected to the drain of PMOS field effect transistor Q2, the source of PMOS field effect transistor Q2 is connected to one end of resistor R3 and the emitter of PNP transistor Q3 respectively, the gate of PMOS field effect transistor Q2 is connected to the other end of resistor R3, the collector of PNP transistor Q3 and one end of resistor R2 respectively. The other end of resistor R1 is grounded. The other end of resistor R2 is grounded.

[0019] In specific implementation, the PNP transistor Q1 and the PNP transistor Q3 are of the same model. The PNP transistor Q1 and the PNP transistor Q3 can be, but are not limited to, any one of 9012, 9015, and MMBT3906. In this embodiment, the PNP transistor Q1 and the PNP transistor Q3 are both MMBT3906.

[0020] These PNP transistor models not only have stable performance, but also are affordable and easy to purchase. They are suitable for various electronic devices and systems, such as audio amplifiers, signal processors, power management circuits, etc. In these devices and systems, they play a vital role to ensure the normal operation and stable performance of the circuit.

[0021] During specific implementation, the model of the PMOS field effect tube Q2 can be but not limited to any one of WPM3407-3, WPM3401-3, and AO3401. In this embodiment, the PMOS field effect tube Q2 is selected as WPM3407-3. The WPM3407-3 type PMOS tube is favored for its low on-resistance and high switching speed, and is particularly suitable for occasions requiring fast response and efficient energy conversion. Whether it is a smart phone, a tablet computer or an industrial control device, these PMOS tube models play an indispensable role. As one of the core components of modern electronic devices, the PMOS tube has various models and different functions, which provides a strong guarantee for the efficient and stable operation of electronic equipment. When selecting a suitable PMOS tube model, it should be comprehensively considered according to the specific application requirements and circuit characteristics to ensure the performance and reliability of the circuit.

[0022] In the circuit of the ideal diode circuit of the utility model, the system input VIN is connected to the drain of the PMOS field effect tube Q2, and the source of the PMOS field effect tube Q2 is connected to the system VOUT output. The gate of the PMOS field effect tube Q2 is connected to the collector of the PNP transistor Q3, and is connected to GND through the resistor R2. The emitter of the PNP transistor Q3 is connected to VOUT, the base of the PNP transistor Q3 is connected to the base of the PNP transistor Q1, and is connected to GND through the resistor R1, and the emitter of the PNP transistor Q1 is connected to VIN.

[0023] Among them, the PNP transistors Q1 and PNP Q2 are of the same model, and the PN junction conduction saturation voltage drop is Vb. The conduction voltage drop of the PMOS field effect transistor Q2 is Vp.

[0024] When VIN inputs a certain voltage, the PNP transistor Q1 is saturated and turned on, and the current passes through the PNP transistor Q1 and the resistor R1 to connect to GND, forming a current loop. At this time, the base voltage of the PNP transistor Q1 is: VB = VIN─Vb.

[0025] Furthermore, VIN is output to VOUT through the body diode of the PMOS field effect transistor Q2. Due to the voltage drop of the body diode, the VOUT voltage is: VOUT = VIN─Vp.

[0026] The emitter and base voltages of the PNP transistor Q3 are:

[0027] VEB=VOUT─VB=(VIN-Vp)─(VIN─Vb)=Vb─Vp<Vb.

[0028] The PNP transistor Q3 is in the cut-off state at this time, and the G pole of the PMOS field effect transistor Q2 is connected to GND through the resistor R2, VG=VOUT×R2 / (R1+R2). According to actual needs, the resistors R1 and R2 are selected to turn on the PMOS field effect transistor Q2.

[0029] After the PMOS field effect transistor Q2 is turned on, it has a lower on-resistance, and the power loss on the PMOS field effect transistor Q2 will be greatly reduced. At this time, although the on-voltage Vp of the PMOS field effect transistor Q2 is reduced, it still exists, and the PNP transistor Q3 will continue to remain in the off state.

[0030] If the VIN power supply suddenly loses power, the PNP transistor Q1 will be cut off, and the output VOUT will form a loop through the PNP transistor Q3 PN junction and the resistor R1. At this time, VB=VOUT─Vb, the PNP transistor Q3 is turned on, VG=VOUT, and the PMOS field effect transistor Q2 is in the cut-off state. VOUT cannot flow to VIN through the PMOS field effect transistor Q2, thus achieving the function of preventing backflow.

[0031] Therefore, the ideal diode circuit of the utility model constitutes an ideal diode circuit. The circuit principle of the ideal diode is based on two important characteristics of the diode: forward conduction and reverse cutoff. When the diode is in forward bias, a potential difference is formed between the P region and the N region, causing the carriers in the P region to migrate to the N region, allowing current to flow. This forward conduction characteristic allows the diode to be used as a current control switch. When the diode is in reverse bias, the potential difference between the P region and the N region will hinder the migration of carriers, making the current almost zero, that is, in the cut-off state.

[0032] Ideal diodes can be used as the basis of functional modules such as rectifiers, voltage regulators, and signal detectors in circuits. Connecting an ideal diode and a resistor in series can achieve a half-wave rectification function, converting an AC signal into a DC signal. By properly designing the circuit, the fast switching function of the diode can also be achieved, and it can be used in applications such as pulse circuits and digital circuits.

[0033] For example, ideal diode circuits can be used in rectifier circuits to convert AC signals into DC signals. Signal inversion and filtering can be achieved, allowing electronic devices to work properly.

[0034] Ideal diode circuits can also be used as key components in signal protection circuits to protect other electronic devices from overvoltage and overcurrent. It can effectively limit voltage and current to avoid equipment damage.

[0035] Ideal diode circuits can also play a very important role in inverter circuits, which can realize the conversion from DC to AC. Inverters are widely used in various fields such as solar power generation, electric vehicle charging, etc.

[0036] Ideal diode circuits can also be used for frequency multiplication and phase control in phase-locked loop circuits. Phase-locked loops have important applications in communications, test instruments, and control systems.

[0037] Ideal diodes can also be used in resonant circuits to help achieve frequency selection and signal filtering. Resonant circuits are widely used in wireless communications, radio frequency identification and other fields.

[0038] The utility model has the beneficial effects of the above embodiments, that is, by using one PMOS tube and two PNP transistors, the circuit is simple, the cost is low, the reliability is high, and the function of low loss and backflow prevention is achieved.

[0039] The present invention is described according to specific embodiments, but those skilled in the art should understand that various changes and equivalent substitutions can be made without departing from the scope of the present invention. In addition, in order to adapt to specific occasions of the present invention technology, many modifications can be made to the present invention without departing from its protection scope. Therefore, the present invention is not limited to the specific embodiments disclosed herein, but includes all embodiments that fall within the scope of protection of the claims.

Claims

1. An ideal diode circuit, characterized in that: include: PNP transistor Q1, PMOS field effect transistor Q2, PNP transistor Q3, resistor R1, resistor R2 and resistor R3; One end of the resistor R1 is respectively connected to the collector of the PNP transistor Q1, the base of the PNP transistor Q1, and the base of the PNP transistor Q3, the emitter of the PNP transistor Q1 is connected to the drain of the PMOS field effect transistor Q2, the source of the PMOS field effect transistor Q2 is respectively connected to one end of the resistor R3 and the emitter of the PNP transistor Q3, and the gate of the PMOS field effect transistor Q2 is respectively connected to the other end of the resistor R3, the collector of the PNP transistor Q3, and one end of the resistor R2.

2. The ideal diode circuit according to claim 1, characterized in that: The other end of the resistor R1 is grounded.

3. The ideal diode circuit according to claim 1, characterized in that: The other end of the resistor R2 is grounded.

4. The ideal diode circuit according to claim 1, characterized in that: The PNP transistor Q1 and the PNP transistor Q3 are of the same model.

5. The ideal diode circuit according to claim 1, characterized in that: The PMOS field effect transistor Q2 is any one of WPM3407-3, WPM3401-3 and AO3401.

6. The ideal diode circuit according to claim 4, characterized in that: The PNP transistor Q1 and the PNP transistor Q3 are any one of 9012, 9015, and MMBT3906.

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