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Single Ended to Differential conversion using two OpAmps - oscillations on output

Category: Hardware
Product Number: AD8512

I am having issues with a common SE to Differential conversion circuit basing on two Op Amps as shown in simulation. The problem I have is oscillations around 1-2 MHz on output. I added a capacitor in parallel to R1 (180 pF), tried different opamps (AD8513, ADA4898, OP4177, OP4227) - frequency shifts, amplitude differs but oscillations still occur. LTSpice shows a peak of gain near 2 MHz.
Could anyone explain my why this happens? What can I do to remove it?

Top Replies

    •  Analog Employees 
    May 8, 2023 in reply to bswiadkowski +1 verified


    Try to change the resistance values of RB RA R7 and R6 to 1k ohm. The possible issue here is that large resistance can induce stability issues.

    You can check this article on the Stability…