SLVSDT1C July 2017 – June 2020 TPSM82480
The soft-start ramp time can be set externally connecting a capacitor between the SS/TR and AGND pins. The capacitor value CSS that is needed to get a specific rising time ΔtSS calculates as:
Because the device has an internal delay time ΔtDELAY from EN=High to start switching, the overall startup time is longer as shown in Figure 8.
If very large output capacitances are used (e.g. >4x47µF), the use of a soft-start capacitor is mandatory to avoid current limit foldback during startup (see Current Limit and Short Circuit Protection).