LMP91000: How to improve Vout Reading

John Lwin

Part Number: LMP91000

Dear TI Experts,

I would like to get your advice for performance of LMP91000SDE/NOPB chip. I am trying to improve Analog Output, Vout reading using Alphasense O2-A3 Oxygen Sensor. At this point of time, I am getting Vout reading of 1.092V for 20.9 % of Oxygen and 1.373 V for 15 %.

I just want to know whether I can get better sensitivity for analogue output, Vout without changing Vref or VDD. I am expecting to get more Vout voltage differences for Oxygen level changes. I have tried different TIA gain setting but it didn’t improve. Below is schematics and POTENTIOSTAT Setting.

Thanks,

John

over 6 years ago

0 Jalen Tate89 over 6 years ago

TI__Genius 9675 points

Hi John,

I am looking into this and will get back with you shortly.

Jalen

0 John Lwin over 6 years ago in reply to Jalen Tate89

Prodigy 140 points

Hi Jalen,

Thanks for your reply. I have got some improvement today. It did change according to the TIA Gain Setting. The higher the gain, the better the result I but . But for now my issues is Vout is unstable for the first 12 hours it keeps on increasing that made me to do incorrect calibration readings. Vout is is a bit noisy for my case as shown below. It could be due to sensor behaviour or could we do something in potentiostat setting??. I will also check with Alphasense about this sensor behaviour as well.

0 Jalen Tate89 over 6 years ago in reply to John Lwin

TI__Genius 9675 points

John,

Have you seen this behavior across multiple sensors?

Jalen

Sensors

Sensors forum

LMP91000: How to improve Vout Reading