P1 Actual Deep Sleep Current

Hardware
1

In working with the P1 in a low power application the datasheet says the deep sleep current is 80uA typical to 100uA max. I have been trying to measure the deep sleep current of my product but was getting lower readings from a uCurrent. I figured I was doing something wrong but then found the following statement made in Managing power for a solar / battery powered core about the deep sleep current datasheet value.

This is based on the P1 reference design which uses the same SMSP as the Photon. Keep in mind you can achieve even lower numbers if you pick a SMPS with super low quiescent current.

I want to confirm that the P1 datasheet is stating the deep sleep current value as the P1 standby current PLUS the specific Richtek SMPS used in the Photon. The Richtek RT8008 has a quiescent current of 50uA typical. Does that mean the P1 itself really has a typical deep sleep current closer to 30uA? If so it's kind of confusing to include an external part's Q current as part of a deep sleep current value.

2

I’m not sure why it’s that way, but I’m pretty sure you are correct.

3 Likes
3

Thanks for the quick response @rickkas7. Would it be possible to have somebody from the engineering side turn the “pretty sure” into a confirmation? Not a confirmation of actual deep sleep current but a confirmation that the value stated in the datasheet includes any current consumption by the Richtek RT8008.

4

It sounds pretty clear to me.

The idle current of the buck converter on the Photon is gone on the P1 since you have to supply your own voltage regulator.

What current are you seeing going into the P1 in Deep Sleep when poweing from a bench power supply at 3.3v?

1 Like
5

I don't have a bench setup going straight into a P1. I have a P1 in my product layout that is supplied by its own power circuitry. With all my supporting components I'm reading 60uA in deep sleep which includes about 30uA of quiescent current from my power block. So I'd estimate it to be around 30uA.

This is my point. I don't think the datasheet is excluding that idle current from the Photon buck converter in the stated deep sleep current value. I think it may also include any other q current in the Photon power setup. I'd like for Particle to confirm and possibly update the datasheet for other product makers. Also I think it would be great for them because, if I'm right, the actual deep sleep current is about a third of the value listed.