When the SMPS does not start up as
expected, the following needs to be checked:
- A very large output capacitance
can cause the converter to hit the overcurrent limit during startup; the hiccup
auto-restart process continues indefinitely
- Change the sense resistor to
allow a higher peak current (and adapt the circuit for the higher current:
MOSFET, inductor and rectifier diode)
- Reduce the output capacitance
(consider higher output ripple)
- Increase the soft-start time
- In general, we know that the
converter might have hit overcurrent protection because COMP pin or CS pin is
hitting the overcurrent threshold, but VOUT is below the regulation
point