Minimum consumption Vl53L3x

Hi,

I plan to use the VL53L3:

The goal is to power it with 1300mah battery, 200ms measurement refresh rate, 2 years life expectancy.

The product could reach <100µA in this conditions ?

Thanks

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ST Employee

That's going to be hard... too hard.

So here's the scoop.

When ranging, the sensor uses 20mA.

so let us assume you range for 20ms per range, 5 ranges per second.

So 20mA * .020seconds *5 ranges = 2mA current draw.

Given 1300mah /2ma = 650 hours.

But please check my math. I'm always getting it wrong.

The other trick is that the host MCU has to be alive to interpret the data from the sensor. And that draws power as well.

So there are some things you can do.

1) switch to the VL53L1X - this sensor runs a different mode that is completely autonomous. Your host can be completely asleep.

it's a touch more expensive though.

You can shorten the ranging time down to 10ms - this will halve the power draw but at the expensive of ranging accuracy.

Range 3x per second.

Doing this gives 20mA * 0.010 second *3 ranges = 0.6mA ... 1300mah /0.6 = 2166 hours.

Unfortunately there are 365*24*2 (17,000)hours in 2 years, so we are still way, way short.

The VL53L4 due our end of year 2021 is supposed to be better, but still not enough for your application.

Sorry about that.

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