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Products => Test Equipment => Topic started by: riforifo on September 24, 2018, 01:49:42 pm

Title: feeding uCurrent output to an ADC
Post by: riforifo on September 24, 2018, 01:49:42 pm

Hello,

I use a Ref200 to generate a 100uA current source and read 99.5 mV with a multimeter.
For a quick test, I also connected the uCurrent output voltage directly with an arduino ADC.

I get varying results between 60mV and 110 mV.
I'll add an moving average algorithm but aside from software,

What are your recommendations for connecting uCurrent output to an ADC
I can try adding an amplifier in  voltage follower mode. Your recommandations are highly appreciated.

thanks

Title: Re: feeding uCurrent output to an ADC
Post by: ogden on September 24, 2018, 01:56:21 pm

Quote from: riforifo on September 24, 2018, 01:49:42 pm

Hello,

I use a Ref200 to generate a 100uA current source and read 99.5 mV with a multimeter.
For a quick test, I also connected the uCurrent output voltage directly with an arduino ADC.

I get varying results between 60mV and 110 mV.
I'll add an moving average algorithm but aside from software,

What are your recommendations for connecting uCurrent output to an ADC
I can try adding an amplifier in  voltage follower mode. Your recommandations are highly appreciated.

thanks

Number one recommandation: match sensor output voltage range to ADC input voltage range. Only then you will have highest resolution of sensor data measurements.

Title: Re: feeding uCurrent output to an ADC
Post by: bson on September 24, 2018, 08:14:42 pm

Look for sources of noise.  The DMM will have an anti-image filter, while a naked ADC pin doesn't.