OPT301: OPT301

Anuja Mehendale

Part Number: OPT301

I wonder if I can have a graph of the output voltage of the device vs constant IR light for OPT301 device. I'm using OP233 IR emitter with 10mA IF. OPR301 is powered with +/-5V. The output of the OPT301 was saturating so a paper filter was used to reduce the intensity of the light. I can now measure 0.8V out of the OPT301. But the issue is it is drifting a lot. Any recommendation on how to get constant output out of OPT301? What is the specification of the outptut voltage vs constant IR light? Ideally, it should be constant.

Thanks

Anuja

over 4 years ago

0 Alex Bhandari-Young over 4 years ago

TI__Mastermind 25895 points

Hi Anuja,

Is the issue you are having related to drift (same light level but light reported changing) or linearity (response not linear across different light intensities?

What is max photodiode current are you reaching in your tests?

Best,

Alex

0 Anuja Mehendale over 4 years ago

Prodigy 120 points

The issue is related to drift and noise. I'm not quite sure about the intensity but I'm powering the IR emitter with 5V with 1K in series which is around 5mA current. The voltage is pretty stable. The measuring device for the OPT301 resolution is 0.3uV per count.

Any suggestions to improve the drift and noise is appreciated. I wonder if TI has done output voltage vs constant light intensity test and can share the data.

please note: The environment that I'm testing is temperature stable and there is no other light being interference.

Thanks

Anuja

0 Alex Bhandari-Young over 4 years ago in reply to Anuja Mehendale

TI__Mastermind 25895 points

Hi Anuja,

Since this is an older part I do not have any further data to provide than what is in the datasheet, unfortunately. Do you have a reference meter that can we used to verify that this light source is not itself drifting?

Best,

Alex

0 Anuja Mehendale over 4 years ago

Prodigy 120 points

What reference meter can I use?

0 Alex Bhandari-Young over 4 years ago in reply to Anuja Mehendale

TI__Mastermind 25895 points

An optical power meter would work. Here are some examples https://www.newport.com/g/optical-power-meters

Best,

Alex

0 Anuja Mehendale over 4 years ago

Prodigy 120 points

Thanks for the link. But the IR emitter uses constant current source so it shouldn't be drifting much. But still worth checking. For Opt 301 what is the drift specification for constant IR light?

0 Alex Bhandari-Young over 4 years ago in reply to Anuja Mehendale

TI__Mastermind 25895 points

Hi Anuja,

I should be able to provide an update on this query by end of this week.

Best,

Alex

0 Alex Bhandari-Young over 4 years ago in reply to Alex Bhandari-Young

TI__Mastermind 25895 points

Hi Anuja,

Can you share the schematic your are using? Specifically Rf and any Cext.

Best,

Alex

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OPT301: OPT301