Microchip Technology DM330031, Руководство пользователя, Страница: 59 / 66

Design Details

2020 Microchip Technology Inc. DS50002927A-page 59
FIGURE C-3: FILTER, FEEDBACK AND BIAS CIRCUIT
Equation C-1 provides the amplifier gain calculations. Equation C-2 and Equation C-3
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)