Question to the REF-Pin of the Converter ADS8861

Andre Wolken

Other Parts Discussed in Thread: ADS8861, REF6050, ADS8881, REF6025

I use the ADS8861 to measure DC-voltages from +5 V to -5 V. I have a reference voltage source which provides 5 V for the REF-pin of the Converter.

In the datasheet on page 9 is described, that the REF-pin has to be decoupled with a 10 µF capacitor. Has it to be decoupled to GND or should the capacitor be in a row between the REF-pin and the reference voltage source?

Thanks for your help.

Best regards,

Andre Wolken

over 7 years ago

0 Abhijeet Godbole over 7 years ago

TI__Expert 5485 points

Hi Andre

REFP pins needs to be decoupled to GND using 10uF capacitor. For sample schematic please refer ADS8861EVM-PDK.

Btw which reference device you are using to power 5V REF pin. TI has recently introduced REF6050 which can be good candidate to drive reference pin.

Thanks

Abhijeet

0 Andre Wolken over 7 years ago in reply to Abhijeet Godbole

Prodigy 20 points

At the monent, i use a reference voltage source from analog devices

0 Abhijeet Godbole over 7 years ago in reply to Andre Wolken

TI__Expert 5485 points

Hi Andre

Thanks for the information

If you are still in design phase then I would like to recommend REF60xx voltage reference family to drive ADS8861 REF pin. REF60xx in industries first voltage reference with integrated ADC drive buffer amplifier. We have REF6025 EVM which has on board ADS8881 which is 18 bit 1MSPS SAR ADC (same footprint as ADS8861, with higher throughput).

You can go through REF6025 EVM users guide which highlights some of the benefits that we get over traditional voltage reference + buffer configuration

http://www.ti.com/lit/ug/sbau258/sbau258.pdf

Thanks & Regards

Abhijeet

Data converters

Data converters forum

Question to the REF-Pin of the Converter ADS8861