SNVS579L February 2009 – May 2018 LM26420
PRODUCTION DATA.
This function forces VOUT to increase at a controlled rate during start-up in a controlled fashion, which helps reduce inrush current and eliminate overshoot on VOUT. During soft start, reference voltage of the error amplifier ramps from 0 V to its nominal value of 0.8 V in approximately 600 µs. If the converter is turned on into a pre-biased load, then the feedback begins ramping from the prebias voltage but at the same rate as if it had started from 0 V. The two outputs start up ratiometrically if enabled at the same time, see Figure 28 below.