8 Application and Implementation

Note

Information in the following applications sections is not part of the TI component specification, and TI

does not warrant its accuracy or completeness. TI’s customers are responsible for determining

suitability of components for their purposes. Customers should validate and test their design

implementation to confirm system functionality.

8.1 Application Information

8.1.1 Single-Ended-to-Differential Gain of 4 V/V

Figure 8-1 shows the configuration that can be used for a single-ended-to-differential gain of 4 V/V. Amplifier A1

follows all the conventional equations of a regular voltage-feedback amplifier for inverting and noninverting

gains. With the fixed inverting gain of –1 V/V for the configuration of A2, the primary role of A2 is to invert the

output of A1 so that a differential signal is available at the output pins, VOUT+ and VOUT–. In the configuration

A2 is equal to the voltage on the VREF pin, which in the case of Figure 8-1 is GND.

A1

+

±

A2

+

±

700

700

1

8

5

±5 V

+5 V

3

OPA862

700

700

4

0.1 µF

0.1 µF

6

7

2

+

±

1 k

1 k

VREF

with respect to GND

Figure 8-1. Single-Ended To Differential Gain of 4 V/V Configuration

Equation 1 through Equation 4 can be derived from the configuration in Figure 8-1. The output common-mode

Equation 4.

F

OUT

IN

G

R

V

V

1

R

§

·

¨

¸

©

¹

(1)

F

OUT

OUT

REF

IN

REF

G

R

V

V

2

V

V

1

2

V

R

§

·

u

u

¨

¸

©

¹

(2)

F

OD

OUT

OUT

IN

REF

G

R

V

V

V

2

V

1

2

V

R

§

·

u

u

¨

¸

©

¹

(3)

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OPA862

SBOS919C – AUGUST 2019 – REVISED AUGUST 2020

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