Multi-signal magnetic isolation transmission circuit with high reliability and application thereof

Abstract

The invention provides a multi-signal magnetic isolation transmission circuit with high reliability and an application thereof. A PWM signal conversion module and a level conversion circuit in the multi-signal magnetic isolation transmission circuit are connected to the primary side of a signal transformer, and a rectifier circuit and a level identification module are connected to the secondary side of the signal transformer. The level conversion circuit regulates the primary voltage of the signal transformer. Multiple PWM signals are input to the PWM signal conversion module and converted into corresponding high-frequency PWM signals. The high-frequency PWM signals are transmitted to the secondary side as primary signals to obtain secondary AC signals. The secondary side generates a secondary voltage. The rectifier circuit restores the secondary AC signals. The level identification module inputs a corresponding recovery voltage. A voltage identification module compares the secondary voltage with the recovery voltage and identifies AC signals corresponding to the recovery voltage. The multi-signal magnetic isolation transmission circuit has high reliability and is less susceptibleto the interference of a strong magnetic field.

Description

technical field [0001] The invention relates to the field of driving circuits, in particular to a multi-signal magnetic isolation transmission circuit with high reliability and its application. Background technique [0002] The magnetically isolated driving circuit can magnetically isolate the driving pulse of the control circuit and the power switch tube. It has the advantages of simple circuit, not easy to damage, low cost, high operating frequency, and minimal delay. It is widely used in the field of switching power supplies. [0003] The block diagram and level diagram of the traditional magnetic isolation drive circuit are shown in figure 1 As shown, after the input signal PWM_X is converted by the conversion circuit, when it is on the rising edge, a positive pulse is generated at both ends of the magnetic signal transformer; correspondingly, when it is on the falling edge, a negative pulse is generated at both ends of the magnetic signal transformer , is transmitted t...

AI Technical Summary

Problems solved by technology

[0004] 1. Susceptible to strong magnetic field interference: The magnetically isolated drive circuit will experience signal anomalies after being subjected to strong magnetic interference, such as increased pulse length, pulse loss, and signal logic reversal, which will inevitably cause changes in the output voltage. which in turn causes unnecessary circuit control problems

For example, if the output voltage is too high and rises to the conduction valve of the main switching tube of the power circuit, it will cause the switching tube to misoperate, which may cause power failure and even endanger the personal safety of the operator.

[0005] 2. There is no error correction mechanism: when there is a problem with the drive circuit, such as an error in the signal state, it cannot be restored, causing the drive signal to reverse, causing the system to crash

[0006] There are also some improvement schemes for the magnetic drive circuit in the prior art. For example, the application number 201210529780.X provides a magnetic drive circuit that can effectively solve the problem of false conduction of the switch tube due to the loss of the duty cycle. Add a discharge circuit on the basis of the discharge circuit to sample the input side pulse signal and discharge the output side, but this circuit can only solve the problem when the pulse signal is lost, and the production cost of the circuit is high and the circuit is complicated

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