Hello! I have a slightly unusual situation in which I want to illuminate the LEDs connected to the outputs of an LP5521 when the board is powered off (So VDD is 0V) by way of an external circuit with its own independent power source. I would like to do this with a minimum of complexity and components.
Without knowing what the internal structure of the output current drivers looks like, I assumed there would be parasitic or intentional diodes in the device that would clamp the outputs to the supply rails. Before asking this question I applied up to about 3V to the outputs of the part, and found that only small (<100uA) currents appear to flow, and the LEDs are illuminated.
Can you tell me whether there is any reason I should not attempt this? If I understand the datasheet correctly, the voltage on R, G, B are limited to 6V, with no mention of the applied Vdd voltage as a limitation. The external drive circuits would be disabled when Vdd to the LP5521 is on.
Thanks!
