INA240A3D - 80V Current Sense Amplifier | Texas Instruments
料号： INA240A3D ✓ 量产中INA240A3D 概述
A current-sense amplifier is a specialized amplifier within the instrumentation-amplifier and signal-conditioning hierarchy. It converts the small differential voltage produced by a shunt resistor into a proportional analog voltage suitable for measurement by an ADC, MCU, motor controller, or protection circuit. The INA240 family is classified as an analog signal-chain IC and is commonly placed beside a power-conversion stage to create a precision current-feedback signal.
The INA240A3D combines bidirectional measurement, a wide -4 V to 80 V common-mode range, and enhanced PWM rejection. Bidirectional operation allows the output polarity to represent either positive or negative current. The negative common-mode capability is useful when a shunt is observed during a below-ground flyback interval, while the upper range supports current monitoring in systems operating well above the amplifier supply voltage. Its stated operating-temperature range is -40 °C to 125 °C.
The device uses a voltage-output architecture with reference and supply connections that support system-level current measurement. Because the amplifier can operate independently of the common-mode voltage being sensed, its performance is maintained in applications where the shunt voltage swings rapidly while the amplifier remains powered from a low-voltage rail. This architecture is particularly useful in motor drives, solenoid controls, power converters, and battery-powered systems where a conventional low-voltage current-sense amplifier may leave the measurement range.
Typical uses include high-side DC-link monitoring, low-side motor-return measurement, solenoid current diagnostics, power-supply telemetry, and battery charge or discharge current sensing. In these systems, the shunt is placed in the current path and connected to the differential input of the INA240A3D. The resulting analog voltage can be routed to a control ADC or comparator for regulation, fault detection, or data logging.
Design the input and reference network carefully because the differential shunt voltage, amplifier supply, output range, and selected shunt resistance jointly determine usable measurement range. Keep the shunt and amplifier connections compact to minimize parasitic pickup, use a Kelvin connection where practical, and route the differential pair away from switching-node copper. The manufacturer's INA240 datasheet should be used for pin assignments, gain, input limits, output behavior, and recommended application values.
This page organizes the verified INA240A3D operating limits, package information, sourcing details, replacement constraints, application guidance, and design considerations. It also distinguishes a confirmed same-package automotive alternative from incompatible package or gain variants that cannot be treated as drop-in replacements.
直接替换替代料： INA240A3D ——相同封装，引脚兼容。需要 PCB 改动的不同封装料号已排除。
本系列中的变体
可与以下型号直接替换的同系列型号： INA240A3D （相同外形与封装尺寸） ——差异在于 Operating Temperature Range.
INA240A3EDRQ1
✅ 直接替换📋 参考替代料（不在目录中）
INA240A3D 最大额定值与电气特性
| Product Type | Bidirectional current-sense amplifier |
| 输出类型 | Analog voltage |
| Common-Mode Voltage Range | -4 V to 80 V |
| Bidirectional Current Sensing | Yes |
| PWM Rejection | Enhanced |
| 工作温度范围 | -40 °C to 125 °C |
| 封装 | 8-pin SOIC (D) |
| Package Width | 3.90 mm |
| 安装类型 | Surface mount |
INA240A3D 3.90 mm 引脚配置指南
INA240A3D（3.90 mm 封装）的引脚配置。 该模拟元件具有输入、输出和电源引脚。请参阅制造商数据手册以了解失调调零、补偿和使能引脚配置。适用于信号调理和放大器电路。
暂无详细引脚数据： INA240A3D.
请参阅 数据手册 以查看完整引脚配置。
典型应用
INA240A3D 适用于 6 应用s: DC-Link Current Monitoring, Motor-Return Current Sensing, Solenoid Flyback Monitoring, Power-Supply Output Telemetry, Battery Charge and Discharge Monitoring, Industrial Overcurrent Protection.
DC-Link Current Monitoring
The INA240A3D fits high-side DC-link monitoring because it senses shunt drops across a -4 V to 80 V common-mode range, independent of the amplifier supply. It is placed beside the power-conductor shunt, and its bidirectional analog output can indicate either charging or discharging current. Enhanced PWM rejection helps prevent switching-node transitions from corrupting the measurement, while the 8-pin SOIC package supports compact industrial and energy-storage control boards.
推荐
Motor-Return Current Sensing
The INA240A3D is suitable for low-side sensing in motor-return or power-return paths where the shunt may experience rapidly changing voltage. Its -4 V to 80 V common-mode capability provides margin across low-voltage motor systems and higher bus voltages, while enhanced PWM rejection improves signal integrity near switching devices. The resulting analog output can be sampled by a motor-control MCU or compared against a threshold for overcurrent protection.
推荐
Solenoid Flyback Monitoring
The INA240A3D can monitor a solenoid or relay current during normal operation and the negative flyback interval. Its common-mode range extends to -4 V, allowing the amplifier to remain accurate when the sensed node moves below ground, while the upper limit of 80 V covers many industrial and automotive load circuits. The voltage output supports diagnostic comparison, current profiling, and protection logic without requiring the shunt voltage to remain close to the amplifier supply.
推荐
Power-Supply Output Telemetry
The INA240A3D is useful in power-conversion modules that must report load current through an analog control signal. Connecting the differential inputs across a shunt permits measurement independent of the shunt's absolute common-mode voltage, and the -4 V to 80 V range accommodates many power stages. Enhanced PWM rejection is valuable when the shunt is upstream of a switching converter, and the 8-pin SOIC format supports a compact, conventional surface-mount layout.
推荐
Battery Charge and Discharge Monitoring
The INA240A3D can measure charge and discharge current in a battery pack because its bidirectional output distinguishes the two current directions. Its broad -4 V to 80 V common-mode range suits systems where the shunt is positioned in a high-side conductor and experiences substantial bus transients. The amplifier provides an analog signal for battery-management controllers, while enhanced PWM rejection supports systems containing switching converters or rapidly varying load currents.
推荐
Industrial Overcurrent Protection
The INA240A3D supports threshold-based protection in industrial power modules by converting a shunt drop into a signal that can be monitored by a comparator or control system. Its 80 V upper common-mode limit covers many 24 V, 36 V, and 48 V power environments, and the -4 V lower limit accommodates negative transients. Bidirectional sensing permits protection in both supply and return paths, while the SOIC package simplifies assembly into control and monitoring boards.
推荐
推荐产品汇总
工程参考数据： INA240A3D ——对比、设计指导和合规信息。
选型指南
与替代料对比
| 参数 | 本产品 | INA240A3EDRQ1 |
|---|---|---|
| Manufacturer | Texas Instruments | Texas Instruments |
| Package | 8-pin SOIC (D) | 8-pin SOIC (D) - same |
| Product Type | Bidirectional voltage-output current-sense amplifier | Bidirectional voltage-output current-sense amplifier |
| Common-Mode Voltage Range | -4 V to 80 V | -4 V to 80 V |
| Gain Family | INA240A3 | INA240A3 |
| PWM Rejection | Enhanced | Enhanced |
| Qualification Class | Industrial | Automotive |
| Output Type | Analog voltage | Analog voltage |
| Bidirectional Sensing | Yes | Yes |
关键差异点
- Wide sensing range above the amplifier supply （对比 INA240A3EDRQ1)
- Bidirectional current measurement （对比 INA240A3EDRQ1)
- Industrial qualification position （对比 INA240A3EDRQ1)
设计说明
Route the differential input pair from the INA240A3D to the shunt as a short, tightly coupled pair. Connect the sense traces directly to the shunt pads using a Kelvin layout, and keep the amplifier-side ground return separate from high-current switching paths. This prevents copper resistance and switching-node displacement from appearing as measurement error.
Do not select an INA240 member solely by the A3 designation when its gain must match an existing PCB. Changing the gain alters the output scaling, ADC interpretation, saturation point, and overcurrent threshold. For a true INA240A3D replacement, verify gain, supply voltage, reference behavior, output range, differential pin functions, and the exact 8-pin SOIC footprint against the manufacturer datasheet.
Use the negative common-mode capability deliberately when sensing a solenoid or motor return that can move below ground. Confirm that both input pins remain within their absolute maximum ratings during every transient, including switch-off overshoot and inductive ringing. Add protection components only after their capacitance, leakage, and clamp voltage have been checked against measurement accuracy and bandwidth requirements.
Enhanced PWM rejection does not remove every switching transient, so keep the amplifier, shunt, and input traces away from high dv/dt copper. Avoid long loops in the differential path, minimize the distance between the shunt and input pins, and maintain a continuous reference ground beneath the analog section. Validate the completed board with a current probe and oscilloscope across the full switching operating range.
合规信息
The INA240A3D is identified as an industrial-temperature device; the automotive-qualified family option is INA240A3EDRQ1. Specific RoHS, REACH, lead-free, halogen-free, and conflict-minerals declarations are not stated in the available results.
