ADS125H02: +/-10V and +/-20mA

Kai Hsiao

Guru 12675 points

Part Number: ADS125H02
Other Parts Discussed in Thread: ADS1262, DAC8775

Hi Sir

We would like to use ADS125H02 to measure +/-10V and +/-20mA

May I know have any reference design or circuit could be refereed ? especially -20mA

Thanks

over 5 years ago

0 Christopher Hall over 5 years ago

TI__Mastermind 44670 points

Hi Kai,

We have short tech doc on using the ADS125H02 for +/- 10V measurements here: http://www.ti.com/lit/an/sbaa387/sbaa387.pdf

For current measurements, we don't have any reference designs specific to the ADS125H02, but we do have some reference designs for a similar device (the ADS1262) which would likely be just as relevant except that for the fact that the input range on the ADS125H02 is much wider. See http://www.ti.com/tool/TIPD164 and http://www.ti.com/tool/TIDA-00550.

I hope that helps!

0 Kai Hsiao over 5 years ago in reply to Christopher Hall

Guru 12675 points

Hi Chris

If use ADS125H02 to measure negative current -20mA (DAC8775 provide)

Could I use below circuit to do ? and connect pin1 and pin4 of J1

0 Christopher Hall over 5 years ago in reply to Kai Hsiao

TI__Mastermind 44670 points

Hi Kai,

It looks like the current source is applied between pins 2 and 3 on J1, and the current is measured as the voltage drop across the R25 burden resistor, is that correct?

I don't see any issue from the circuit as you've drawn it. Some times there may be a TVS diode across the burden resistor to protect it in case of mis-wiring. Just take care to ensure that the burden resistor's power dissipation is never exceeded in case of an electrical overstress (EOS) event.

Also, if you haven't already, I'd recommend taking a look at the ADS125H02 Design Calculator (Rev. A) to double check that the input common-mode voltage is within range of the ADS125H02. With the wide input-range of the ADS125H02, it shouldn't be an issue.

0 Christopher Hall over 5 years ago in reply to Christopher Hall

TI__Mastermind 44670 points

Hi Kai,

FYI: Collin recently posted an additional reference circuit for the ADS125H02 over on this E2E thread, which you may find applicable to your design:

0 Kai Hsiao over 5 years ago in reply to Christopher Hall

Guru 12675 points

Hi Chris

Thanks for your reply

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ADS125H02: +/-10V and +/-20mA