AD628

Rev. C | Page 18 of 20

FILTER CAPACITOR VALUES

low-pass filter. The capacitor value is

()

μF

C =

Table 7 shows several frequencies and their closest standard

capacitor values.

Table 7. Capacitor Values for Various Filter Frequencies

Frequency (Hz)

Capacitor Value (µF)

10

1.5

50

0.33

60

0.27

100

0.15

400

0.039

1 k

0.015

5 k

0.0033

10 k

0.0015

KELVIN CONNECTION

In certain applications, it may be desirable to connect the

inverting input of an amplifier to a remote reference point. This

eliminates errors resulting in circuit losses in interconnecting

wiring. The AD628 is particularly suited for this type of

connection. In Figure 35, a 10 kΩ resistor is added in the

feedback to match the source impedance of A2, which is

described in more detail in the Gain Adjustment section.

+IN

–IN

A2

5V

–IN

+IN

OUT

CIRCUIT

LOSS

LOAD

+IN

–IN

G = +0.1

A1

AD628

10k

Ω

10k

Ω

10k

Ω

100k

Ω

100k

Ω

10k

Ω

Figure 35. Kelvin Connection