OPA314: Will this circuit be susceptible to oscillations?

Darren (FAE)

Part Number: OPA314
Other Parts Discussed in Thread: ADS1015,

I have a question on the stability of a design using the OPA314 and ADS1015.
There will be a differential signal to the OPA314 inputs, and the output will go to ADS1015.

Schematic

Do you see any concerns with this circuit?

over 3 years ago

0 kai klaas69 over 3 years ago

Guru 140200 points

Hi Darren,

I cannot open the link.

Kai

+1 Ron Michallick over 3 years ago

TI__Guru*** 139946 points

Hello Darren,

Zero chance of oscillation. The bandwidth is 100Hz, was that intentional?

+1 Former Member over 3 years ago

Hi Darren,

I ran a quick stability simulation and you should be fine with around 72° of phase margin. The isolation resistor will stabilize your circuit. I do wonder why the customer wants to use such a large load/charge kick back capacitor.

The input impedance of the ADS1015 is not well-defined in the data sheet, but seems inconsequential especially given the load you have placed on the output. I would say, I am not sure if that 12kΩ resistor is actually supposed to be 12.4kΩ. Seems like that is a possible typo.

Let me know if you need any further help.

Regards,
Daniel

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OPA314: Will this circuit be susceptible to oscillations?