AD8210

Rev. 0 | Page 13 of 16

INPUT FILTERING

In typical applications such as motor and solenoid current

sensing, filtering at the input of the AD8210 can be beneficial in

reducing differential noise, as well as transients and current

ripples flowing through the input shunt resistor. An input low-

pass filter can be implemented as shown in Figure 32.

The 3 dB frequency for this filter can be calculated using the

following formula:

FILTER

FILTER

C

R

f

×

×

π

=

2

1

dB

3

_

(1)

introduces additional errors to the system. To minimize these

internal input resistors of the AD8210, a gain error is

introduced. This can be calculated using the following formula:

⎟

⎟

⎠

⎞

⎜

⎜

⎝

⎛

−

×

−

=

FILTER

R

Error

Gain

kΩ

2

kΩ

2

100

100

(%)

(2)

AD8210

OUTPUT

G= +20

+IN

–IN

GND

0.1µF

Figure 32. Input Low-Pass Filtering