SNVSBK9C November 2019 – September 2020 LM63635-Q1
The forced PWM mode (FPWM) can be used to turn off AUTO mode and force the device to switch at the frequency programmed by the RT pin, even for small loads. This has the disadvantage of lower efficiency at light loads.
When a valid clock signal is present on the SYNC/MODE input, the switching frequency is locked to the external clock. The device mode is also FPWM. The mode can be changed dynamically by the system. See Figure 8-10 and Figure 8-11 for typical examples of SYNC/MODE function changes.