OUTMIN

MIN

SENSE

V

I

R

GAIN

u

u

SP

SENSE

MAX

V

R

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I

GAIN

u

ENABL E

VS

OUT

GND

IN+

IN±

LOA D

0.1 F

5 V

12 V

TI-Device

TM

21

INA191

www.ti.com

SLYS020A – FEBRUARY 2019 – REVISED APRIL 2019

Product Folder Links: INA191

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Copyright © 2019, Texas Instruments Incorporated

8.2 Typical Applications

8.2.1 Microamp Current Measurement

The low input bias current of the INA191 provides accurate monitoring of small-value currents. To accurately

monitor currents in the microamp range, increase the value of the sense resistor to increase the sense voltage

so that the error introduced by the offset voltage is small. The circuit configuration to monitor low-value currents

kΩ or less for best accuracy.

Figure 40. Measuring Microamp Currents

8.2.1.1 Design Requirements

The design requirements for the circuit shown in Figure 40, are listed in Table 1

Table 1. Design Parameters

DESIGN PARAMETER

EXAMPLE VALUE

5 V

12 V

1 µA

150 µA

Device gain (GAIN)

25 V/V

8.2.1.2 Detailed Design Procedure

The maximum value of the current-sense resistor is calculated based choice of gain, value of the maximum

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