AFE4490: AFE4490 ADC measuring voltage range

Kil Hwan Roh

Prodigy 10 points

Part Number: AFE4490

Hi,

I'm KH and I wondering AFE4490 ADC measuring voltage range.

By datasheet of AFE4490, LED1 and LED2 sample range is from +/- 1.2V.

What I wonder is why from -1.2V to 0V are needed to ADC measure.

Thank you in advance.

over 1 year ago

+1 Praveen Aroul over 1 year ago

TI__Mastermind 49666 points

Hello KH,

From the PPG signal perspective, the PD current will be positive but with ambient cancelation DAC to remove any DC component in the signal followed by the 2nd stage gain, the signal could end up negative.

0 Kil Hwan Roh over 1 year ago in reply to Praveen Aroul

Prodigy 10 points

Hi Praveen, thank you for your answer.

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AFE4490: AFE4490 ADC measuring voltage range