Design Details
2020 Microchip Technology Inc.
DS50002927A-page 59
FIGURE C-3:
FILTER, FEEDBACK AND BIAS CIRCUIT
provides the amplifier gain calculations.
and
provide the equations to calculate cutoff frequencies of the Differential-mode and
Common-mode filters.
EQUATION C-1:
AMPLIFIER GAIN
EQUATION C-2:
CUTOFF FREQUENCY DIFFERENTIAL-MODE FILTER
EQUATION C-3:
CUTOFF FREQUENCY COMMON-MODE FILTER
C2
R
IN
R
IN
C1
C2
R
F
R
F
R
IN
R
IN
A
B
C
D
E
F
R
IN2
R
IN1
R
IN1
R
IN2
Differential Amplifier Gain
=
Rf
(
R
IN1
+ R
IN2
)
Differential-mode f
–3
dB
1
2
(
R
IN1
+ R
IN2
)
C
2
2 +
C
1
Common-mode f
–3
dB
1
2
(
R
IN1
)(
C
2)
