Current-doubling synchronous rectification circuit

In the case of high current output, the manufacturing process of the midpoint tap transformer is complex and costly. However, the current doubler synchronous rectification circuit shown in Figure 1 does not require a midpoint tap transformer and uses two filter inductors, which is easy to manufacture and low in cost.

Figure 1 Timing of control signals

Figure 2 Current-doubling synchronous rectification circuit

The current-doubling rectifier circuit can be used in half-bridge or full-bridge converters. Its working principle is: when the same-name terminal of the transformer is positive, SR1 is turned on, SR2 is turned off, inductor L1 stores energy through the transformer and SR1, and provides electrical energy to the load, and inductor L2 releases electrical energy to the load through SR2; conversely, when the same-name terminal of the transformer is negative, SR2 is turned on, SR1 is turned off, the inductor field stores energy through the transformer and SR2, and provides electrical energy to the load, and inductor Ly releases electrical energy to the load through SR2.

It can be seen that when combined with the same primary circuit, the relationship between the control logic of the eye in the current-doubling synchronous rectification circuit and the main switch tube is the same as that of the SR tube in the full-wave rectification circuit.