• GAIN is the gain of the current-sense amplifier.

Table 9-1 shows an example of the different results obtained from using five different gain versions of the

INA241x. From the table data, the highest gain device allows a smaller current-shunt resistor and decreased

power dissipation in the element.

PARAMETER

EQUATION

A1, B1

DEVICES

A2, B2

DEVICES

A3, B3

DEVICES

A4, B4

DEVICES

A5, B5

DEVICES

G

Gain

10 V/V

20 V/V

50 V/V

100 V/V

200 V/V

Ideal differential input voltage

500 mV

250 mV

100 mV

50 mV

25 mV

Current sense resistor value

50 mΩ

25 mΩ

10 mΩ

5 mΩ

2.5 mΩ

Current-sense resistor power dissipation

5 W

2.5 W

1 W

0.5 W

0.25 W

(1)

Design example with 10-A full-scale current with maximum output voltage set to 5 V.

9.2 Typical Application

The INA241x is a bidirectional, current-sense amplifier capable of measuring currents through a resistive shunt

with shunt common-mode voltages from –4 V to +110 V.

9.2.1 Current Sensing in a Solenoid Application

GND

MCU

24 V

Solenoid

5 V

INA

R

SENSE

I

SENSE

ADC

Figure 9-1. Solenoid Drive Application Circuit

9.2.1.1 Design Requirements

In this example application, the common-mode voltage ranges from 0 V to 24 V. The maximum sense current is

1.5 A, and a 5-V supply is available for the INA241x. Following the design guidelines from RSENSE and Device

Table 9-2 lists the design setup for this application.

Table 9-2. Design Parameters

DESIGN PARAMETERS

EXAMPLE VALUE

Power supply voltage

5 V

Common mode voltage range

0 V to 24 V

Maximum sense current

1.5 A

50 mΩ

Gain option

50 V/V

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INA241A, INA241B

SBOSA30 – MARCH 2022

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