OPT3101: OPT3101 receives amplitude saturation

Hi Pengsheng, 

Could you please provide more details of the testing conditions? Which light source and photodiode are you using? What ambient light conditions? Which mode during the test? How many parts do you see the issue?

Thank you.

Wenjuan

Wenjuan,

       I tested using Auto HDR mode, and tested using OPT3101 Configurator Tool to generate configuration files;My test is to open the SDK INLAB_STEP_0 conditional compilation, serial print amplitude, phase, temperature and other data

       In the case of the photodiode, the amplitude data was saturated, so I removed the photodiode from the PCBA after testing, and the amplitude data read was still saturated;The photodiode I used was BPV22NF

       Using the same software, I was able to read the normal amplitude data using the OPT3101 EVM hardware

       The first time this happened!

       Thanks!!!!

Pengsheng,

Thank you for the details.

Could you let me know what calibrations have you done? Have you removed the crosstalk?

Best regards,

Wenjuan

Wenjuan

        Before the OPT3101 calibration, it is necessary to open conditional compilation INLAB_STEP_0, determine the calibration distance parameters according to the actual calibration target board and the amplitude value required for calibration, and write the calibration distance parameters into the refDistancesInMM array. However, the current phenomenon is that I open conditional compilation INLAB_STEP_0. Read the amplitude signal data is 65535, can not determine the calibration distance, can not calibrate, I will remove the receiving photodiode, read the amplitude signal data is still 65535, is my description clear, I can not carry out subsequent calibration under the current conditions, without receiving the photodiode in the case of amplitude data saturation may be what?

        Thanks!!!

Pengsheng, 

I have some questions to help trouble shooting the saturation issue. 

At what driver bias current do you see the issue? 

Do you see the issue on one board or all the boards?

Thank you.

Wenjuan

Wenjuan，

      These are the driving currents I set up to test：

      The same phenomenon was found in all three PCBA tests！！

      After I removed the infrared emitting diode and receiving photodiode, the amplitude data printed by the serial port was still 65535

      This is the test I did,

      Thanks！！！

Pengsheng, 

If you see the saturation issue even without emitting diode and photodiode, it is not due to light conditions. 

Have you tried to test under low current setting, whether you will still see the issue?

If the same issue is found on all the boards, we may need review the board layout. 

Thank you.

Wenjuan

Wenjuan,

   The test reduces the high and low threshold current of TX0 channel, the minimum is 2.8mA/1.4mA. The amplitude signal data printed by the serial port without receiving the photodiode is still 65,535 and saturated. Is this high probability caused by PCB layout?

   Thanks!