Device

3 V

1 MW

60 kW

100 kW

1 MW

NTC

Thermistor

Device

ADS1100

Load

V

I C

2

R

1

4.99 kW

R

3

4.99 kW

R

4

48.7 kW

R

2

49.9 kW

+5 V

3 V

REF3130

R

7

1.18 kW

R

SHUNT

1 W

R

6

71.5 kW

R

N

56 W

R

N

56 W

(PGA Gain = 4)

FS = 3.0 V

Stray Ground-Loop Resistance

I

LOAD

R

1

V

EX

V

OUT

V

REF

R

1

Device

R

R

R

R

+5 V

OPA317

OPA2317

OPA4317

www.ti.com

SBOS682A – MAY 2013 – REVISED JUNE 2013

APPLICATION CIRCUITS

Figure 21 shows the basic configuration for a bridge amplifier. A low-side current shunt monitor is shown in

Figure 22.

Figure 21. Single Op Amp Bridge Amplifier

NOTE: 1% resistors provide adequate common-mode rejection at small ground-loop errors.

Figure 22. Low-Side Current Monitor

16-bit converter; therefore, a precise reference is essential for maximum accuracy. If absolute accuracy is not

required and the 5-V power supply is sufficiently stable, the REF3130 may be omitted.

Figure 23 shows the OPA317 in a typical thermistor circuit.

Figure 23. Thermistor Measurement

Copyright © 2013, Texas Instruments Incorporated

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Product Folder Links: OPA317 OPA2317 OPA4317