I built a low pass filter with ADA4522
Officially recommended filter circuit with no feedback resistance
However, the ADA4522 manual recommends increasing the feedback resistance
In this application, do we need to increase the feedback resistance?
Hi seekyong,
I think you're referring to ADA4522 datasheet Figure 75 where a finite feedback resistor (instead of a direct short) is used for a buffer configuration.
I don't think you'd need to worry about excess input current flow (due to the input clamp circuit turning on). With LTspice simulation, the maximum diff input signal is limited to +/-3.5mVp which is not enough to turn on the clamps. The signal that reaches the non-inverting input is sufficiently slowed down by R4, and C4 in your schematic (this is my rationale, but I could be wrong):
Here is the simulation file if you'd like to experiment with it in LTspice:
Regards,
Hooman
Hi seekyong,
I think you're referring to ADA4522 datasheet Figure 75 where a finite feedback resistor (instead of a direct short) is used for a buffer configuration.
I don't think you'd need to worry about excess input current flow (due to the input clamp circuit turning on). With LTspice simulation, the maximum diff input signal is limited to +/-3.5mVp which is not enough to turn on the clamps. The signal that reaches the non-inverting input is sufficiently slowed down by R4, and C4 in your schematic (this is my rationale, but I could be wrong):
Here is the simulation file if you'd like to experiment with it in LTspice:
Regards,
Hooman
