OPT3101: OPT3101 laser pulse period

mahiro.aikawa

Prodigy 80 points

Part Number: OPT3101

Tool/software:

I have a question about the OPT3101 laser pulse period.

OPT3101 always acquires data at 4000Hz and determines the sampling rate with NUM_SUB_FRAMES.

In other words, 4000 pieces of data are divided by NUM_SUB_FRAMES, averaged, and the measurement is calculated.

This is written in the data sheet "7.3.1.3 Non-HDR Mode".

So, I'm curious about the laser pulse during measurement. Can you tell me the number of times the laser pulse lights up per second and the lighting period?

5 months ago

0 Gordon Varney 5 months ago

TI__Genius 9310 points

Mahiro-san,

The sub frame is 10k clocks, from a 40Mhz osc. The total processing time is 0.25ms. The maximum number of times you can turn on the emitter is 4000 times a second. The total on period is 8192 clocks out of the 10000 clocks subframe.

0 mahiro.aikawa 5 months ago in reply to Gordon Varney

Prodigy 80 points

Additional question.
"The total on period is 8192 clocks out of the 10000 clocks subframe."
For each part, when are the 8192 on periods out of the 10000?

Is my guess correct?
8192 on periods → 1808 off periods → 8192 on periods → 1808 off periods → ...

0 Gordon Varney 5 months ago in reply to mahiro.aikawa

TI__Genius 9310 points

Mahiro-san,

Yes you are correct. During active sampling it just repeats. During the off periods, the emitter may be off but the OPT3101 is still processing in the background until the next subframe.

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OPT3101: OPT3101 laser pulse period