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V

COM OUTPUT

−

R

1

R

3

R

2

C

1

C

2

V

CC

10 F

(a) Using V

COM to Bias a Single−Supply Filter Stage

(b) Using a Voltage Follower to Buffer V

COM When Biasing Multiple Nodes

(c) Using an INA134 for DC−Coupled Output

x = L or R

10 F

Filtered

Output

OPA337

2

3

1

A

V = −1, where AV =

R

2

R

1

V

OUTx

V

COM

V

COM

P C M 17 4 2

+

+

Buffered

V

COM

V

CC

V+

V−

V

CC

+

1/2

OP A 2353

10 F

P C M 1 74 2

25k

Ω

25k

Ω

49.9k

Ω

1%

25k

Ω

25k

Ω

SENSE

OUT

−IN

+IN

REF

x = L or R

10 F

To Low−Pass

Filter Stage

INA134

V

OUTx

V

COM

P C M 17 4 2

+

µ

µ

µ

µ

PCM1742

SBAS176A – DECEMBER 2000 – REVISED APRIL 2005

One unbuffered common-mode voltage output pin, VCOM (pin 10), is brought out for decoupling purposes. This

pin is nominally biased to a dc voltage level equal to VCC/2. This pin can be used to bias external circuits. An

example of using the VCOM pin for external biasing applications is shown in Figure 27.

Figure 27. Biasing External Circuits Using the VCOM Pin

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