68.6.2.5.1 PWM Push-Pull Mode

When a PWM channel is configured in Push-Pull mode, the dead-time generator output is managed alternately on each PWM cycle. The polarity of the PWM line during the idle state of the Push-Pull mode is defined by the DPOLI bit in the PWM Channel Mode Register (PWM_CMRx). The Push-Pull mode can be enabled separately on each channel by writing a one to bit PPM in the PWM Channel Mode Register.

Figure 68-11. PWM Push-Pull Waveforms: Left-Aligned Mode

Figure 68-12. PWM Push-Pull Waveforms: Center-Aligned Mode

The PWM Push-Pull mode can be useful in transformer-based power converters, such as a half-bridge converter. The Push-Pull mode prevents the transformer core from being saturated by any direct current.

Figure 68-13. Half-Bridge Converter Application: No Feedback Regulation

Figure 68-14. Half-Bridge Converter Application: Feedback Regulation