SLUS984C November 2009 – April 2018 TPS51200-Q1
The soft-start function of the VO pin is achieved through a current clamp. The current clamp allows the output capacitors to be charged with low and constant current, providing a linear ramp-up of the output voltage. When the VO pin is outside of the powergood window, the current clamp level is one-half of the full overcurrent limit (OCL) level. When the VO pin rises or falls within the PGOOD window, the current clamp level switches to the full OCL level. The soft-start function is completely symmetrical and works not only from GND to the REFOUT voltage, but also from the VLDOIN pin to the REFOUT voltage.