-5V

V-

Optional

(2)

C

100nF

1

R

(1)

100W

1

R

50kW

2

C

100nF

2

V+

+5V

SD1

BAS40

V

0to4.096V

IN

ADS8326

16-Bit

250kSPS

C

(1)

1nF

3

C

100nF

4

+5V

REFIN

-IN

+IN

REF3240

4.096V

+5V

OPA320

1/2

OPA2320

1/2

OPA2320

R

3

25kW

R

2

25kW

R

G

R

1

100kW

R

4

100kW

R

L

10kW

V

OUT

50kW

G=5+

200kW

R

G

+5V

+5V

REF1004-2.5

4

8

(2.5V)

+5V

OPA320, OPA2320

OPA320S, OPA2320S

SBOS513E – AUGUST 2010 – REVISED JUNE 2013

www.ti.com

DRIVING ADCS

The OPA320 can be used to buffer the ADC switched

input capacitance and resulting charge injection while

The OPA320 series op amps are well-suited for

providing signal gain. Figure 44 shows the OPA320

driving sampling analog-to-digital converters (ADCs)

configured to drive the ADS8326.

with sampling speeds up to 1MSPS. The zero-

crossover distortion input stage topology allows the

OPA320 to drive ADCs without degradation of

differential linearity and THD.

Figure 43. Two Op Amp Instrumentation Amplifier with Improved High-Frequency Common-Mode

Rejection

(1) Suggested value; may require adjustment based on specific application.

(2) Single-supply applications lose a small number of ADC codes near ground as a result of op amp output swing limitation. If a negative

power supply is available, this simple circuit creates a –0.3V supply to allow output swing to true ground potential.

Figure 44. Driving the ADS8326

18

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