CN207884494U - A kind of positive-negative power generation circuit suitable for IGBT drivings - Google Patents

Abstract

The utility model discloses a kind of positive-negative power generation circuits suitable for IGBT drivings,It is related to IGBT drive circuit,Solve in the prior art Zener diode come the technical problems such as voltage stabilized range when generating positive-negative power is limited,It includes input power,Voltage stabilizing chip,Zener diode and resistance,There are two coupling capacitors for connection between input power,Node connection between the anode of Zener diode and the capacitor C2 and capacitor C3,The plus earth of Zener diode,One end of its cathode and resistor connects,The other end of resistor is connected to input voltage,Input voltage and the input terminal of voltage stabilizing chip connect,Node between resistor and Zener diode cathode is connected with the signal ground of voltage stabilizing chip,The low-voltage output of the output end connection positive-negative power generation circuit of voltage stabilizing chip,Low-voltage output is connected with capacitor C1,The other end of capacitor C1 is grounded.The structure design of the utility model is reasonable, is easy to manufacture, and voltage regulation result is good.

Description

A Positive and Negative Power Generation Circuit Suitable for IGBT Driving

technical field

The utility model relates to an IGBT drive circuit, in particular to a positive and negative power supply generation circuit suitable for IGBT drive.

Background technique

The capacitance and peak problems caused by the Miller effect are a relatively common situation in daily work. In the operation of the IGBT module, if the Miller capacitance problem is not dealt with in time, it is easy to cause damage to the IGBT. In the daily work process, once the parasitic capacitance problem of the Miller effect occurs during the operation of the IGBT module, it is often seen in the obvious 0 to 15V type gate driver, which is what engineers often call a single-supply driver. Gate-collector-electrode coupling During IGBT turn-off, high du/dt transients can induce parasitic IGBT pass-through, that is, gate-collector voltage spikes, which is a potential hazard for the IGBT and even the entire machine . Generally, in order to prevent the occurrence of parasitic IGBT channels, there are usually three solutions. The first is to add capacitance between the gate and emitter to the configuration, the second is by driving with a negative gate voltage, and the third is to change the gate resistance. If the first solution is used, the power consumption of the driving power will increase, and the switching loss of the IGBT will also increase under the same gate drive resistance. The second option requires consideration of additional costs and costs. The third method will increase the turn-on loss.

When the IGBT module is working, the driving power is too high, which will cause the short-circuit current to be too large, and even break down the IGBT gate. If the driving power is too low, it will cause serious heating of the IGBT and reduce the life of the IGBT. Due to the existence of parasitic Miller capacitance, high turn-off du/dt will charge the gate, resulting in false turn-on of IGBT, so a negative power supply is required for reliable turn-off. In the prior art, Zener diodes are generally used to generate positive and negative power supplies, but the Zener diodes have a limited voltage stabilization range, and the voltage stabilization effect will be reduced when the input power fluctuates.

Utility model content

The purpose of the utility model is to provide a positive and negative power generating circuit suitable for IGBT driving, which can reduce the fluctuation of the output power when the fluctuation range of the IGBT driving input power is too large.

The utility model specifically adopts the following technical solutions in order to achieve the above object:

A positive and negative power generation circuit suitable for IGBT driving, comprising an input power supply, a voltage stabilizing chip, a Zener diode and a resistor R1, two coupling capacitors are connected between the input power supplies, and capacitor C2 and capacitor C3 are connected in series, The anode of the Zener diode is connected to the node between the capacitor C2 and the capacitor C3, the anode of the Zener diode is connected to the ground, the cathode thereof is connected to one end of the resistor R1, and the other end of the resistor R1 is connected to the input voltage , the input voltage is connected to the input terminal of the voltage stabilizing chip, the node between the resistor R1 and the cathode of the Zener diode is connected to the signal ground of the voltage stabilizing chip, and the output terminal of the voltage stabilizing chip is connected to positive and negative The low-voltage output terminal Vo of the power generation circuit is connected to a capacitor C1, and the other end of the capacitor C1 is grounded.

Working principle: The IGBT drive input power supply is connected in series with two voltage-dividing capacitors C2 and C3, and the resistor R1 and Zener diode are connected in series and then connected in parallel to one of the voltage-stabilizing capacitors C2. The voltage across the resistor R1 is taken as the input of the voltage-stabilizing chip. The output terminal of the voltage regulator chip is connected to the filter capacitor C1 and the capacitor C2 terminal, the voltage Vo across the capacitor C1 is the output positive power supply, and the voltage across the capacitor C3 is the output negative power supply. When the input power fluctuates, as long as it is greater than the minimum voltage of the Zener diode, the voltage regulator can stably output positive power Vo and negative power.

Beneficial effects of the utility model: Compared with the prior art, the present invention utilizes the wide input voltage range of the voltage stabilizing chip and high-precision voltage stabilizing output, as long as the power supply voltage is higher than the minimum voltage of the Zener diode, a stable output can be obtained Voltage, which expands the range of input power fluctuations and also solves the problem of output fluctuations.

Description of drawings

Fig. 1 is the structural representation of the utility model.

Detailed ways

In order to make the purpose, technical solutions and advantages of the utility model clearer, the utility model will be further described in detail below in conjunction with the examples and accompanying drawings. The schematic implementation of the utility model and its description are only used to explain the utility model Novelty, not as a limitation to the utility model.

As shown in Figure 1, this implementation provides a positive and negative power generation circuit suitable for IGBT driving, including an input power supply, a voltage regulator chip U1, a Zener diode Zd, and a resistor R1, and two couplings are connected between the input power supplies The capacitor is connected in series between the capacitor C2 and the capacitor C3, the anode of the zener diode Zd is connected to the node between the capacitor C2 and the capacitor C3, the anode of the zener diode Zd is grounded, and its cathode is connected to one end of the resistor R1, The other end of the resistor R1 is connected to the input voltage VSS, the input voltage VSS is connected to the input terminal vin of the voltage stabilizing chip U1, and the node between the resistor R1 and the cathode of the Zener diode Zd is connected to the voltage stabilizing chip U1 The signal ground of the voltage regulator chip U1 is connected to the ground gnd, the output terminal vout of the voltage stabilizing chip U1 is connected to the low voltage output terminal Vo of the positive and negative power supply generation circuit, the low voltage output terminal Vo is connected to the capacitor C1, and the other end of the capacitor C1 is grounded.

In this embodiment, the IGBT drive input power supply is connected in series with two voltage dividing capacitors C2 and C3, the resistor R1 and the Zener diode Zd are connected in series and then connected in parallel to one of the voltage stabilizing capacitors C2, and the voltage at both ends of the resistor R1 is taken as the voltage stabilizing chip The input of U1, the output terminal vout of the voltage regulator chip is connected to the filter capacitor C1 to the capacitor C2 terminal, the voltage Vo across the capacitor C1 is the output positive power supply, and the voltage across the capacitor C3 is the output negative power supply. When the input power fluctuates, as long as it is greater than the minimum voltage of the Zener diode Zd, the voltage regulator can stably output positive power Vo and negative power.

The above is only a preferred embodiment of the utility model, and is not intended to limit the utility model. The scope of patent protection of the utility model is subject to the claims. Equivalent structural changes should be included in the protection scope of the present utility model in the same way.

Claims (1)

1. a kind of positive-negative power generation circuit suitable for IGBT drivings, it is characterised in that：Including input power (VSS；GND)、 Voltage stabilizing chip U1, Zener diode Zd and resistance R1, the input power (VSS；GND there are two coupling capacitors for connection between) (C2, C3) connects between capacitor C2 and capacitor C3, and the anode of the Zener diode Zd is connected to capacitor C2 and capacitance On node between device C3, the Zener diode Zd plus earths, cathode is connect with one end of resistance R1, the resistance R1 The other end be connected to input voltage VSS, input voltage VSS is connect with the input terminal vin of the voltage stabilizing chip U1, the resistance Node between R1 and Zener diode Zd cathodes is connected with the signal ground gnd of the voltage stabilizing chip U1, the voltage stabilizing chip The low-voltage output Vo of the output end vout connection positive-negative power generation circuits of U1, low-voltage output Vo are connected with capacitor C1, The other end of capacitor C1 is grounded.