What Is a Push-Pull Converter?

A push-pull circuit is an output circuit connected between two transistors of different polarities. The push-pull circuit uses two power BJT tubes or MOSFET tubes with the same parameters and exists in the circuit in a push-pull manner. Each is responsible for the positive and negative half-cycle waveform amplification tasks. When the circuit works, there are only one symmetrical power switch at a time Conduction, so small conduction loss and high efficiency. The push-pull output can sink or draw current from the load.

Push-pull circuit

If there are two triodes in the output stage, they are always in an on and off state, that is, the two triodes are push-pull connected. Such a circuit structure is called a push-pull circuit or

Push-pull circuits are suitable for low voltage and high current applications, and are widely used in power amplifier circuits and switching power supplies.

The advantage is:

The structure is simple, the utilization ratio of the magnetic core of the switching transformer is high, and when the push-pull circuit works, only two of the two symmetrical power switch tubes are turned on at a time, so the conduction loss is small.

weakness is:

The transformer has a center tap and the switching tube withstands a higher voltage. Due to the leakage inductance of the primary side of the transformer, the moment the power switching tube is turned off, the drain-source electrode will generate a large voltage spike. In addition, the ripple of the input current is relatively small. Large, so the size of the input filter is large.