ZHCSB48B May 2013 – January 2019 TPS55330
PRODUCTION DATA.
The TPS55330 PWM control system has a minimum PWM pulse width of 77ns (typical). This minimum on-time determines the minimum duty cycle of the PWM, for any set switching frequency. When the voltage regulation loop of the TPS55330 requires a minimum on-time pulse width less than 77ns, the IC enters pulse-skipping mode. In this mode, the device will hold the power switch off for several switching cycles to prevent the output voltage from rising above the desired regulated voltage. This operation typically occurs in light load conditions when the PWM operates in discontinuous conduction mode. Pulse skipping increases the output ripple as shown in Figure 22.