Push-Pull Mode

In Push-Pull mode, two output signals are generated, alternating copies of the input as illustrated in Figure 1. This alternation creates the Push-Pull effect required for driving some transformer-based power supply designs. Steering modes are not used in Push-Pull mode. A basic block diagram for the Push-Pull mode is shown in Figure 2.

The Push-Pull sequencer is reset whenever EN = 0 or if an auto-shutdown event occurs. The sequencer is clocked by the first input pulse, and the first output appears on CWGxA.

The unused outputs CWGxC and CWGxD drive copies of CWGxA and CWGxB, respectively, but with polarity controlled by the POLC and POLD bits, respectively.

Figure 1. CWG Push-Pull Mode Operation
Figure 2. Simplified CWG Block Diagram (Push-Pull Mode, MODE = ‘b101)