AMC7836: Setting up Device for ADC only usage

ANIRUDRA DIWAKAR

Prodigy 20 points

Part Number: AMC7836

Hello,

I want to set up AMC7836 as a 16 channel bipolar ADC to measure analog inputs ranging -5V to +5V.

Question 1 >> Do I need to power up the DAC portion (AVCC & AVEE) of the IC for this operation?

More precisely, my power supply is as follows,
IOVDD +3V3
DVDD +5V
AVDD +5V

(REF_CMP is left NC - using internal 2.5v reference)

Question 2 >> Will the ADC map [-12v to +12v] Analog inputs to [0 - 2xVref] output range on this configuration?

over 6 years ago

0 Paul_Frost over 6 years ago

TI__Guru 53773 points

Hi Anirudra,

Q1. The AVCC/AVSS much still be connected, but they do not need to be high-voltage. AVCC can be tied to 5V, AVSS can be grounded. Note that REF_CMP is not NC, it still should have the compensation capacitor connected to it.
Q2. The low voltage LV_ADCs will still be mapped to 0V to 5V. The high-voltage inputs will still be mapped to -12.5V to 12.5V, even with the lower supplies.

Thanks,
Paul

0 ANIRUDRA DIWAKAR over 6 years ago in reply to Paul_Frost

Prodigy 20 points

Thank you for the prompt response.

Additionally, Can you please elaborate the capacitor denoted by C38 as NI in the pinout diagram of AMC7836EVM User Guide (Page 21/30). I'm not sure what is meant by NI.

0 Paul_Frost over 6 years ago in reply to ANIRUDRA DIWAKAR

TI__Guru 53773 points

Hi Anirudra,

The 'NI' stands for "not installed", only the 4.7µF cap is required.

Thanks,
Paul

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AMC7836: Setting up Device for ADC only usage