SLVSFS6A May 2021 – September 2021 TPS629210-Q1
The TPS629210-Q1 has two operating modes: Forced PWM mode discussed in this section, and Auto PFM/PWM mode as discussed in Section 8.4.3.
With the MODE/S-CONF pin set to Forced PWM mode, the device operates with pulse width modulation in continuous conduction mode (CCM) with a nominal switching frequency of either 1.0 MHz or 2.5 MHz. The frequency variation in PWM is controlled and depends on VIN, VOUT, and the inductance. The on time in forced PWM mode is given by Equation 3.
For very small output voltages, an absolute minimum on time of about 50 ns is kept to limit switching losses. The operating frequency is thereby reduced from its nominal value, which keeps efficiency high.