Our product has the ST1S14PHR step-down regulator to supply 5V to the rest of the board. The input voltage range to the regulator is 8V to 24V, and the output is 5V at 1A max. We are seeing start up issues with the supply during power supply ramp test where the input supply starts at 2V and goes up 1V per second up to 28 V and then down to 2V. About 1 out 100 ramp cycles, the regulator does not start up. However, we have not seen any start up issues during normal power cycling tests where the input 24V supply switched on for 15 seconds and off for 5 seconds with a relay. Let us know if anyone has seen this issue, and how it was resolved. Any help is appreciated. Thanks.
