we use a MPM3510A to convert +36V into +5V. We have connected a LED with cathode to the PG signal. We connected +5V via resistor of 270 Ohm to the anode of the LED. We see a short flash when we enable/disable the MPM. But in on state LED stays off. Datasheet only states that it is an open drain signal which may drive up to 4 mA.
Can you explain this behaviour?
We use another MPM3506A with the same circuit. Difference is that we convert from 36V to 30V and have another LED resistor of 2k7 to +30V. But the LED is on when the MPM is on.
Welcome to the MPS Technical Forum! Can you please share a schematic of both circuits? What is the p/n and Vf of the LED you are using? High volume customers can also send their questions to mpsnow@monolithicpower.com for specialized support from our FAE team.