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AD822 Unity Gain Stability

Question asked by veerasamy on Aug 16, 2016
Latest reply on Aug 16, 2016 by harryh

Hi,

We are using AD822 as a Buffer circuit driving ADC. The Datasheet mentions that the device is capable of driving 350pF Capacitive Load at Unity Gain. However the Phase Margin of OPAMP is only about 45 degree (Figure - 16 of datasheet). With Output Impedance being 300 ohm at Unity Gain frequency (1.8MHz), the Phase Margin will be less than 20 degree with 350pF Load.

In this case, How can we assume, the OPAMP will be stable with 350pF Load? Thanks in advance.

 

Regards,

Veerasamy

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