JAJSH37A August 2019 – August 2019 TPS56C230
PRODUCTION DATA.
The TPS56C230 has an internal 1.2-ms soft-start time, and also an external SS pin is provided for setting longer soft start time if needed. When the EN pin becomes high, the soft-start function begins ramping up the reference voltage to the PWM comparator.
If the application needs a longer soft start time, it 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 2:
where