Hello,
I am using the LMR14203 to charge a buffer of an LED flasher. The buffer is 20x 47uF/16V MLCC capacitor. The supply voltage is 24V and the buffer voltage is 9V. During the LED flash the buffer voltage will drop 4V. The LMR14203 will recharge the buffer in about 20ms. Basically this works ok, but I did find a problem.
The image below shows the pulse trigger (yellow) vs the buffer voltage (red). The trigger will pulse the LED 4 times in a row and then skip one. This is intended behaviour.
You see when the pulse is skipped the buffer voltage will remain the same after the trigger. Then however, the interesting part starts. The first pulse after the ignored one will draw 4V out of the buffer. Contrary to what I would expect the LMR14203 does not start to recharge the buffer at this moment. Only after the 2nd pulse, if the buffer voltage drops even lower, the recharge starts. After that, each pulse gives the response I would expect.
My guess is that the sudden voltage drop activates the short circuit protection. But if this is the case I would expect this to happen at each pulse.
Is there a way I can improve this behaviour?