As a differential input impedance of an OP amp, 30 kOhm seems to be too low. A typo?
LME49722
Z_IN Differential Input Impedance 30 kΩ
Z_CM Common Mode Input Impedance –10V ≤ VCM ≤ 10V 1000 MΩ
SNAS454A –MARCH 2008–REVISED APRIL 2013
Copyright © 2013, Texas Instruments Incorporated
There seem to be errors in the description of some figures. For example, "IMD vs Frequency" for Figure 11 seems to be wrong. The horizontal axis looks like voltage axis, not frequency axis.
LME49722
Z_IN Differential Input Impedance 30 kΩ
Z_CM Common Mode Input Impedance –10V ≤ VCM ≤ 10V 1000 MΩ
SNAS454A –MARCH 2008–REVISED APRIL 2013
Copyright © 2013, Texas Instruments Incorporated
There seem to be errors in the description of some figures. For example, "IMD vs Frequency" for Figure 11 seems to be wrong. The horizontal axis looks like voltage axis, not frequency axis.
Not a typo.
The input impedance of 1000M is because the input current changes very, very little during feedback operation.
However, if there is a difference in the input voltages (overdrive past proper feedback or use as a comparator) then there will be a small amount of current flow...hence the 30K.
🙂
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