nPM1304 LEDDRV causes unexpected 300 µA current consumption

RE: nPM1304 LEDDRV causes unexpected 300 µA current consumption

mathiaso — Fri, 18 Sep 2026 08:49:50 GMT

[quote user="Fryderyk"]It would be great if this information (the ~300 µA shared bias current when any
LED driver is enabled) could be added to the next revision of the product
specification.[/quote]

I've forwarded this internally.

[quote user="Fryderyk"]One follow-up question: with the nPM1304, would you consider it a good solution
to connect the LED directly to VSYS instead? We are aware that the LED
brightness will then vary with the battery voltage and we are fine with that.
Is there anything on the nPM1304 side that speaks against it?[/quote]

It should be fine to do that and control the LED with, e.g., a GPIO-controlled FET. However, another option could also be to use one of the load switches with its input connected to VSYS, as these have a very low quiescent current.

RE: nPM1304 LEDDRV causes unexpected 300 µA current consumption

Fryderyk — Thu, 17 Sep 2026 12:40:24 GMT

Hi Mathias,

Thank you for the confirmation, that explains our measurements exactly.

It would be great if this information (the ~300 µA shared bias current when any
LED driver is enabled) could be added to the next revision of the product
specification.

We would honestly have liked to use the LED drivers, but for our application
300 µA is simply too much of the power budget, so we will not be using them.

One follow-up question: with the nPM1304, would you consider it a good solution
to connect the LED directly to VSYS instead? We are aware that the LED
brightness will then vary with the battery voltage and we are fine with that.
Is there anything on the nPM1304 side that speaks against it?

RE: nPM1304 LEDDRV causes unexpected 300 µA current consumption

mathiaso — Thu, 17 Sep 2026 12:22:47 GMT

Hi again.

I've had it confirmed that this seems to be as expected. When enabling the LED drivers, the consumption will be ~100µA per driver, so 300µF for 3 drivers sounds right. This is the quiescent current for the drivers, plus the necessary references. It is 300µA, regardless of how many drivers are enabled, because the bias current is shared by all three drivers.

Best regards,
Mathias

RE: nPM1304 LEDDRV causes unexpected 300 µA current consumption

mathiaso — Wed, 16 Sep 2026 16:06:07 GMT

Hi.

I've created an internal ticket on this and will get back to you as soon as I receive a response.

Best regards,
Mathias