SLVSDI8C october 2016 – august 2023 TPS568215
PRODUCTION DATA
The TPS568215 has an adjustable soft-start time that can be set by connecting a capacitor on SS pin. When the EN pin becomes high, the soft-start charge current (ISS) begins charging the external capacitor (CSS) connected between SS and AGND. The devices tracks the lower of the internal soft-start voltage or the external soft-start voltage as the reference. The equation for the soft-start time (TSS) is shown in Equation 3:
where
If the output capacitor is pre-biased at startup, the device initiates switching and starts ramping up only after the internal reference voltage becomes greater than the feedback voltage VFB. This scheme ensures that the converters ramp up smoothly into regulation point.