OPT3101: Sample Rate in Super-HDR Mode

Stefan L

Prodigy 40 points

Part Number: OPT3101

Hello everyone,

How is the sample rate of OPT3101 calculated for Super-HDR mode?

In Non-HDR mode the formula is:

In Auto-HDR mode one additional sub-frame is added: with HDRmode = 1.

Is it the same for Super-HDR mode or is here a second additional sub-frame added for validation of the amplitude?

In my application OPT3101 is used in Super-HDR mode with an averaging filter of 16.
So for Non-HDR mode sample rate would be 4000 / 16 = 250 Hz.
For Auto-HDR mode sample rate should be 4000 / 17 = 235 Hz.

Against theory, I measure for my application in Super-HDR mode a sample rate of about 248 Hz.
Measured with Data_Rdy signal on GP1 pin.
Configuration was done with Configurator Tool and SDK.

Is there an explanation for this sample rate?

Thank you.

Stefan

over 3 years ago

0 Brent Elliott over 3 years ago

TI__Expert 6800 points

Hi Stefan,

Looking into this.

Thank you,

Brent Elliott

0 Stefan L over 3 years ago

Prodigy 40 points

Hi Brent,

Thank you for your help.

Concerning the measuring of sample rate in my application:

The time period between Data_Rdy pulses sometimes jumps to a longer period.
Maybe, as if there are additional sub-frames.
But overall, the average pulse rate measured is 248 Hz.

Stefan

0 Brent Elliott over 3 years ago in reply to Stefan L

TI__Expert 6800 points

Hi Stefan,

Super-HDR should have the same sample rate as Auto-HDR. Can you let me know what pulse rate you are measuring for non-HDR and auto-HDR mode to correlate your measurements?

Thank you,

Brent Elliott

0 Stefan L over 3 years ago in reply to Brent Elliott

Prodigy 40 points

Hi Brent,

For each mode I measure the same pulse rate, there is no difference.

Stefan

+1 Brent Elliott over 3 years ago in reply to Stefan L

TI__Expert 6800 points

Hi Stefan,

The additional subframe that you are talking about is a decision sub-frame which will be thrown out if the output is invalid. If this subframe is valid, then the rest of the frame is counted up and the amount of subframes is the same as in non-HDR mode. The only instance where there will be an additional subframe is if the first subframe output is invalid and the illumination DAC current needs to be switched, which will only happen if the target is moving between the two ranges of the DAC currents.

So the sample rate will be the same for all modes, with the exception that one additional subframe will occur only when the device is switching DAC currents.

Thank you,

Brent Elliott

0 Stefan L over 3 years ago in reply to Brent Elliott

Prodigy 40 points

Thank you.

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OPT3101: Sample Rate in Super-HDR Mode