VL53L4CD Power consumption measurement

[AElgh]

Hello Everyone, 
I'm using the VL53L4CD with the STM32WL55JC1, The following is the Power Profile of the cycle:

1- XSHUT GPIO is normally pulled low.

2- XSHUT Pulled up + delay ( sensor wakes up).

3- VL53L4CD Initiliazation.

4- Measurements (20 Samples).

5- XSHUT Pulled Low again.

Just after the initializing of the VL53L4CD, the current consumption was 4.45uA, then after HW-Standby, I can't get less than 332uA!?

Why this high amount of consumption even if the XSHUT is Pulled Low?

The used board is the Sparkfun board(the LED on the board is removed).

I posted this question inside another topic but I think it's better to be alone(since the sensor is different).

Thank you

Amir

[Anne BIGOT]

Hello Amir,

We did replicate your setup with :

- a X-Nucleo-53L4A1 board from ST

- a X-Nucleo-LPM0A1 board from ST for power conso measurement

as per the picture below

Using the Cube IDE STM32 example code delivered in the VL53L4CD ULD package, modified to match your test description and we got :

0.152 µA on AVDDVCSEL and 0µA on AVDD

Could it be that you have power conso on I2C ? What are the pull-up resistors you are using on the I2C pins (as per table 3 and 4 of the datasheet) ?

Regards

Anne

[AElgh]

Hello Anne,

Thank you for your reply, If what you mean by "power conso" is a typo of power consumption on I2C, then the answer is no(I'll explain below with the power profile graph), otherwise please explain what you meant.

The pullup resistor values for the use module are 2.2kohm(I also tried to activate the internal pullups of the MCU but the results were almost the same).

As I wanted to know which line of code changed the consumption of the HW-Standby from 4.45uA(Original Post) to around 330uA, I ran the following:

- VL53L4CD_ULD_V2.1.1 Driver used.

- VDD: 3.3V.

- XSHUT: Normally High(No Internal Pullup).

- XSHUT-GPIO & I2C Clocks will be Disabled after the Sensor goes to HW-Standby.

I put a few seconds of delay between every line of code that modifies the sensor's registers in the initialization function and draw the power profile it as follows:

Observation 1: The high consumption that starts to happen during HW-Standby starts after the "Start VHV" Line.

Observation 2: Stop Ranging Command does not affect the Power Consumption!!

Observation 3: Removing XSHUT-Pin Manually seems to stop some leakage current happening there(I'm thinking of how to simulate the same behavior in SW).

What do you think?

Amir

[AElgh · Accepted solution]

Ok, i found a solution, turning the XSHUT-Pin into Analog after HW-Standby Solved the issue:

[SLERO.1]

@AElgh 

Thank you to share how you did.:grinning_face:

I got the same result as you after HW-Standby , 312uA

To solve this 312uA consumption, I have completely cut the power of the sensor when no need to use it. 

Now consumption is 0

In both cases, if you use Xshut or cut the power, new init must be done. So it's better to save more power.

And we are using our own PCB

[6313oscar]

How did you connect the rest of the I/O to the Lidar? I have got a similar issue where my custom pcb consumes 100 μA more when using the lidar. 

I do not use the LIDARint pin, Xshut does not really seem to work with my application and is pulled down by the mcu.

after each measurement I turn my mosfet off, but there seems to be 1.8V leaking in somewhere.