INA240A3D - 80V Current Sense Amplifier | Texas Instruments
MPN： INA240A3D ✓ 啟用中INA240A3D 概覽
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.
直接替換替代品，適用於 INA240A3D — 相同封裝，腳位對腳位相容。需重新設計 PCB 的不同封裝零件不列入。
此系列的變體
與下列產品可直接替換的同系列型號： INA240A3D （相同外形與佔位） — 差異在於 Operating Temperature Range.
INA240A3EDRQ1
✅ 直接替換📋 參考替代品（不在目錄中）
INA240A3D 最大額定值與電氣特性
| Product Type | Bidirectional current-sense amplifier |
| 輸出類型 | Analog voltage |
| Common-Mode Voltage Range | -4 V to 80 V |
| Bidirectional Current Sensing | Yes |
| PWM Rejection | Enhanced |
| 工作溫度範圍 | -40 °C to 125 °C |
| 封裝 | 8-pin SOIC (D) |
| Package Width | 3.90 mm |
| 安裝類型 | Surface mount |
INA240A3D 3.90 mm 腳位配置指南
INA240A3D（3.90 mm 封裝）的腳位配置。 此類比元件具有輸入、輸出與電源腳位。偏移歸零、補償與致能腳位配置請參閱製造商資料表。適用於訊號調理與放大器電路。
無詳細腳位定義資料： INA240A3D.
請參閱 資料表 以查看完整腳位配置。
典型應用
INA240A3D 適用於 6 應用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.
推薦
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.
推薦
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.
推薦
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.
推薦
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.
推薦
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.
推薦
推薦產品摘要
工程參考資料，適用於 INA240A3D — 比較、設計指引及合規資訊。
選型指南
與替代品比較
| 參數 | 本產品 | 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 |
主要差異化特點
- Wide sensing range above the amplifier supply (對比INA240A3EDRQ1)
- Bidirectional current measurement (對比INA240A3EDRQ1)
- Industrial qualification position (對比INA240A3EDRQ1)
設計說明
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.
合規資訊
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.
