7Semi INA240 4-80V Bidirectional Current Sensor Amplifier Breakout Board

Overview

The 7Semi INA240 Breakout Board is a precision current-sense amplifier module based on the Texas Instruments INA240 IC.

It is designed for accurate bidirectional current measurement in systems with high voltage and noisy switching signals (like PWM motor drives).

Working Principle

• Measures voltage drop across an external shunt resistor

• Uses a high-precision differential amplifier

• Converts small shunt voltage amplified analog output voltage

• Output is proportional to current (both directions)

Supports:

• Forward current

• Reverse current (charging/discharging systems)

Core Electrical Characteristics

• Common-mode voltage range: 4V to +80V

• Sli>Quiescent current: ~2.4 mA

• Operating temperature: 40C to +125C

Can measure current even in high-side configurations (on supply line)

Gain Variants (Important)

Different versions of INA240 provide fixed gain:

• 20 V/V (INA240A1)

• 50 V/V (INA240A2)

• 100 V/V (INA240A3)

• 200 V/V (INA240A4)

Gain determines:

• Sensitivity

• Measurement range

Key Technical Features

Wide Voltage Capability

• Works from 4V to 80V common-mode

• Handles below-ground transients

Bidirectional Sensing

• Detects:

  • Charging current

  • Discharging current

High Accuracy

• Zer very small shunt voltages (~10 mV)

High Noise Immunity

• PWM rejection technology

• Stable output even in:

  • Motor drivers

  • Switching power supplies

High CMRR

• ~132 dB (DC) excellent noise rejection

Output Characteristics

• Type: Analog voltage output

• Output equation (concept):

  Vout = Gain (Vshunt)

• Can be read using:

  • Microcontroller ADC

  • Analog measurement systems

Functional Capabilities

• High-side current sensing

• Low-side current sensing

• Fast response for dynamic loads

• Suitable for high-frequency switching systems

Internal Architecture

• Precision differential amplifier

• Zero-drift offset correction

• High-speed analog ircuitry

Performance Characteristics

• Fast response time suitable for real-time control

• High bandwidth handles switching signals

• Stable output without ripple (PWM systems)

Key Technical Advantages

• Works in noisy electrical environments

• Measures both directions of current

• High accuracy even at low current levels

• Supports wide voltage systems (up to 80V)

Limitations

• Requires external shunt resistor

• Output is analog (needs ADC for digital systems)

• Accuracy depends on:

  • Shunt resistor quality

  • PCB layout

Technical Summary

This module is a high-precision analog current sensing solution, ideal for:

• High-vos

• Real-time current monitoring

Compared to simple sensors (like ACS712), it provides:

• Much higher accuracy

• Better noise rejection

• Faster response</