OPT3001-Q1: inconsistent result read out

Masatoshi Oguri

Part Number: OPT3001-Q1

Hello,

One of my customers found an inconsistent read out from result register like shown in the below picture.

The frequency of data reading here is 40ms where the conversion mode is 800ms. Thus, the device should return the same data for 20 readings, but somehow just one data is different in a transition of light level.

Similar thing is also found in start up of the device. For 800ms of power-on the read out should be all 00, but the customer sometimes sees 00FF and FF00.

Do you have any idea what causes this?

Thank you.

Regards,

Oguri (TIJ automotive FAE)

over 6 years ago

0 Alex Bhandari-Young over 6 years ago

TI__Mastermind 25895 points

Hi Masatochi,

For light transition how is the light transition happening? is it possible that the light source does go higher and then settles during the transition?

Best,

Alex

0 Masatoshi Oguri over 6 years ago in reply to Alex Bhandari-Young

TI__Expert 4780 points

Hi Alex,

No, it is not possible. Because the register read is once in 40ms while the conversion mode is 800ms, a single data cannot be different. This singular data appears occasionally. Not every time, but not very rare.

Oguri

0 Masatoshi Oguri over 6 years ago in reply to Masatoshi Oguri

TI__Expert 4780 points

Hi Alex,

Haven't you seen similar situations anywhere else?

Thanks.

Oguri

0 Alex Bhandari-Young over 6 years ago in reply to Masatoshi Oguri

TI__Mastermind 25895 points

Hi Masatoshi,

I have not seen this before and had contacted our design team to take a look, but am still waiting to hear back. In the meantime I had a couple more questions aswell.

1. Is the problem repeatable?
2. Can you put the device in single-shot mode and see if the reading changes?

Best,

Alex

0 Alex Bhandari-Young over 6 years ago in reply to Alex Bhandari-Young

TI__Mastermind 25895 points

Hi,

If you still need help here let me know and we can take this offline to email. You can contact me at bhandari at ti.com

Best,

Alex

0 Masatoshi Oguri over 6 years ago in reply to Alex Bhandari-Young

TI__Expert 4780 points

Hi,

How long should the user wait from power up if he or she wants a valid response at the first read out?
The conversion mode is configured 800ms.
I guess it should be 800ms plus some milliseconds for some start-up process.

Oguri

0 Alex Bhandari-Young over 6 years ago in reply to Masatoshi Oguri

TI__Mastermind 25895 points

Hi,

The device will power up in shutdown mode and needs to be configured. After voltage supply is stable the device can be configured over I2C. Then after the conversion time the reading can be read.

Best,

Alex

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OPT3001-Q1: inconsistent result read out