INA2181A3IDGSR - 26V Dual-Channel Current Sense Amp | TI
料号： INA2181A3IDGSR ✓ 量产中| 数量 | 单价 | 小计 |
|---|---|---|
| 1 | $0.49 | $0.49 |
| 10 | $0.44 | $4.40 |
| 100 | $0.38 | $38.00 |
| 500 | $0.33 | $165.00 |
| 1,000 | $0.29 | $290.00 |
INA2181A3IDGSR 概述
A current sense amplifier (also called a current-shunt monitor) is a specialized difference amplifier that senses the small voltage drop across a shunt resistor and converts it into a ground-referenced output signal. Within the power-management IC hierarchy, it sits alongside voltage regulators and battery-management devices as a core building block of power monitoring and protection subsystems.
Key features include the wide -0.2 V to +26 V common-mode range that operates independently of the supply voltage, enabling high-side and low-side sensing on 24 V industrial rails. The A3 gain option of 100 V/V with a 2 V/us output slew rate and 350 kHz bandwidth suits fast, medium-sensitivity current monitoring. Offset voltage is tightly specified: a maximum of plus/minus 150 uV at VCM = 0 V and plus/minus 500 uV at VCM = 12 V, according to the TI datasheet.
The INAx181 architecture senses bidirectional current with an external reference voltage applied to the REF pin, allowing the output to be offset for positive and negative current indication. Rail-to-rail output swing maximizes ADC dynamic range on low-supply rails, and the cost-optimized design targets volume production.
Typical applications include battery charging systems, 24 V industrial power supplies, motor drive DC bus monitoring, and telecom or server power-supply current telemetry where two channels share one shunt scheme or monitor two rails.
Design consideration: keep the shunt resistor value and the A3 gain of 100 V/V balanced - a 10 mV full-scale shunt drop yields 1 V output, so size the shunt to use the ADC input range without exceeding the output swing limits.
This page synthesizes distributor pricing, drop-in alternatives within the INAx181 family, and practical design notes not found in the manufacturer datasheet.
直接替换替代料： INA2181A3IDGSR ——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： INA2181A3IDGSR （相同外形与封装尺寸） ——差异在于 Output Type, Package, Common-Mode Voltage Range, Channels, Qualification.
快速对比工具——选择替代料号进行并排对比：
INA2181A2IDGSR
✅ 直接替换✓ 有现货
$0.19 / 个
查看数据手册 →INA2181A1QDGSRQ1
✅ 直接替换✓ 有现货
$0.35 / 个
查看数据手册 →INA2181A4QDGSRQ1
✅ 直接替换✓ 有现货
$0.72 / 个
查看数据手册 →INA2181A1IDGSR
✅ 直接替换 ⚠️ 规格未核验✓ 有现货
$0.52 / 个
查看数据手册 →INA2181A4IDGSR
✅ 直接替换 ⚠️ 规格未核验📋 参考替代料（不在目录中）
INA2181A3IDGSR 最大额定值与电气特性
| Number of Channels | 2 |
| Gain (A3 option) | 100 V/V |
| Bandwidth | 350 kHz |
| Common-Mode Voltage Range | -0.2 V to +26 V |
| Offset Voltage (VCM = 0 V) | ±150 uV (maximum) |
| Offset Voltage (VCM = 12 V) | ±500 uV (maximum) |
| Output Slew Rate | 2 V/us |
| Sensing Type | Bidirectional, high-side or low-side |
| 输出类型 | Voltage output, rail-to-rail |
| 工作温度范围 | -40C to +125C |
| 封装 | 10-pin VSSOP (DGS) |
| 安装类型 | Surface Mount |
| RoHS 状态 | Compliant |
INA2181A3IDGSR 引脚配置
| 引脚 1 | OUT1 — Channel 1 output voltage |
| 引脚 2 | GND — Ground reference |
| 引脚 3 | REF1 — Channel 1 reference voltage (sets zero-current baseline) |
| 引脚 4 | IN1- — Channel 1 inverting input (connect to shunt negative side) |
| 引脚 5 | IN1+ — Channel 1 non-inverting input (connect to shunt positive side) |
| 引脚 6 | IN2+ — Channel 2 non-inverting input |
| 引脚 7 | IN2- — Channel 2 inverting input |
| 引脚 8 | REF2 — Channel 2 reference voltage |
| 引脚 9 | VS — Power supply |
| 引脚 10 | OUT2 — Channel 2 output voltage |
典型应用
INA2181A3IDGSR 适用于 6 应用s: Battery Charge/Discharge Monitoring, 24V Industrial Power Supply Monitoring, Motor Drive DC Bus Current Sensing, Telecom and Server Power Telemetry, Automotive Body Electronics and Load Monitoring, Solar Charger and Energy Harvesting Systems.
Battery Charge/Discharge Monitoring
The INA2181A3IDGSR fits battery management front ends because its bidirectional sensing architecture distinguishes charge from discharge current, and its -0.2 V to +26 V common-mode range covers 12 V and 24 V battery stacks independent of the 3.3 V or 5 V supply. With the A3 gain of 100 V/V, a 20 mOhm shunt yields 2 V of output swing at 1 A, and the ±150 uV maximum offset at VCM = 0 V keeps low-current accuracy within roughly 1.5 mA of shunt-referred error. Each REF pin is driven to mid-supply by a reference so the two channels report signed current around a baseline. Unlike ADC-integrated monitors, this part adds no digital bus latency and its 350 kHz bandwidth captures fast transients during load steps.
推荐
24V Industrial Power Supply Monitoring
Industrial 24 V rails demand current monitors whose common-mode range tolerates the full bus voltage regardless of the local supply, and the INA2181A3IDGSR's -0.2 V to +26 V VCM range does exactly that. The dual channels let one IC monitor both a main rail and an auxiliary rail, halving BOM count versus two single-channel monitors. The 100 V/V gain supports small shunts (e.g., 10 mOhm for 1 V output at 1 A), minimizing heat dissipation in the shunt. The ±500 uV maximum offset at VCM = 12 V bounds mid-scale error, and the 350 kHz bandwidth detects inrush and short-circuit events quickly enough for protection firmware to react. The rail-to-rail output preserves resolution on low-voltage ADC references.
推荐
Motor Drive DC Bus Current Sensing
In three-phase motor drives, DC bus current telemetry provides input for power-limiting and fault algorithms. The INA2181A3IDGSR monitors the bus shunt with a 2 V/us slew rate and 350 kHz bandwidth, capturing PWM-related ripple so the control MCU sees average current without heavy filtering delay. Bidirectional sensing with the REF pin offset at mid-supply captures regenerative braking currents that flow back into the bus. The 26 V common-mode rating covers 12 V and 24 V drive buses, and dual channels can separately monitor the bus and a brake chopper. Because the part is voltage-output, no digital isolator handshake is required on low-side referenced designs, keeping loop latency to the amplifier's own propagation delay.
推荐
Telecom and Server Power Telemetry
Telecom -48 V systems and server backplanes require continuous current telemetry on multiple rails. The INA2181A3IDGSR provides two independent monitors in one 10-pin VSSOP, conserving board area on dense power boards. Its rail-to-rail output interfaces directly to 3.3 V ADCs, and the 100 V/V gain accommodates the 1 mOhm to 10 mOhm shunts typical of high-current server rails (for example, 5 mOhm and 50 A produces a 2.5 V output at 100 V/V, suitable for a 3.3 V ADC range after scaling). The extended -40C to +125C operating range covers equipment rooms with aggressive thermal budgets, and the -0.2 V VCM floor tolerates momentary ground offsets during hot-insert events.
推荐
Automotive Body Electronics and Load Monitoring
Automotive 12 V loads such as lighting modules, pumps, and actuators need cost-optimized current monitoring for diagnostics and protection. For these systems the Q1-qualified family members sharing this pinout (INA2181A1QDGSRQ1, INA2181A4QDGSRQ1) are recommended, and the standard INA2181A3IDGSR serves non-automotive industrial variants of the same platform. The 26 V common-mode rating withstands load-dump-like rail excursions up to the absolute maximum, dual channels monitor high-beam/low-beam or pump/stage pairs, and the fast 350 kHz response flags short circuits within microseconds. The VSSOP-10 footprint keeps per-channel monitoring cost and area low in body-control modules built in high volume.
推荐
Solar Charger and Energy Harvesting Systems
Solar charge controllers must measure both panel current and battery current with high efficiency. The INA2181A3IDGSR's dual channels can monitor the panel input and battery output simultaneously using one IC, with independent REF references for bidirectional battery flow. The -0.2 V common-mode floor allows low-side sensing near ground potential where panel return currents flow, while the 26 V ceiling covers typical 12 V and 24 V panel arrays with margin. The 100 V/V gain lets designers use very small shunts (e.g., 5 mOhm at 10 A gives 0.5 V output), limiting shunt power loss to 0.5 W and preserving harvested energy. The low cost suits consumer and light-industrial solar products.
推荐
推荐产品汇总
工程参考数据： INA2181A3IDGSR ——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 | INA2181A2IDGSR | INA2181A1QDGSRQ1 | INA2181A4QDGSRQ1 | INA2181A4IDGSR |
|---|---|---|---|---|---|
| Package | 10-pin VSSOP (DGS) | 10-pin VSSOP (DGS) - same | 10-pin VSSOP (DGS) - same | 10-pin VSSOP (DGS) - same | 10-pin VSSOP (DGS) - same |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Gain | 100 V/V (A3) | 50 V/V (A2) | 20 V/V (A1) | 200 V/V (A4) | 200 V/V (A4) |
| Channels | 2 | 2 | 2 | 2 | 2 |
| Common-Mode Range | -0.2 V to +26 V | -0.2 V to +26 V | -0.2 V to +26 V | -0.2 V to +26 V | -0.2 V to +26 V |
| Bandwidth | 350 kHz | 350 kHz | 350 kHz | 350 kHz | 350 kHz |
| Offset Voltage (max, VCM = 0 V) | ±150 uV | ±150 uV | ±150 uV | ±150 uV | ±150 uV |
| Automotive Grade (AEC-Q100) | No | No | Yes (Q1) | Yes (Q1) | No |
| Operating Temperature | -40C to +125C | -40C to +125C | -40C to +125C | -40C to +125C | -40C to +125C |
关键差异点
- Mid-family gain balancing bandwidth and resolution （对比 INA2181A2IDGSR)
- Cost-optimized dual-channel integration （对比 INA2181A1IDGSR)
- Standard-grade option where Q1 is unnecessary （对比 INA2181A4QDGSRQ1)
设计说明
Use a dedicated Kelvin connection from the shunt resistor terminals to the IN+ and IN- pins. Route the sense traces as a closely coupled differential pair directly from the shunt pads; never tap the sense lines from power traces carrying full load current, because parasitic copper resistance (a few milliohms) becomes gain error. With the 100 V/V A3 gain, 1 mOhm of extra series resistance in the sense path with a 10 mOhm shunt adds roughly 10% reading error. Keep the shunt and amplifier within a few millimeters of each other.
Decouple the VS pin with a 0.1 uF ceramic capacitor placed within 2 mm of the pin, plus a bulk 1 uF capacitor on the rail. The REF1 and REF2 pins must be driven from a low-impedance source - a resistor divider alone is inadequate because any divider impedance adds directly to offset and gain error; buffer the divider with an op amp or use a precision reference such as a shunt regulator. Size the REF voltage to keep the output within swing limits at maximum bidirectional current: with a 3.3 V supply, mid-supply 1.65 V REF allows roughly +/-1.6 V of current-signal headroom at 100 V/V gain.
Do not exceed the 26 V common-mode limit on the IN pins even transiently, since automotive load-dump events can far exceed this. Verify that shunt voltage at maximum fault current stays within the input differential range of the amplifier. Note that the gain is factory-fixed at 100 V/V - if a design later needs different sensitivity, the only drop-in path is another INAx181 gain grade in the same footprint, so select the shunt with headroom for gain changes. Finally, budget the ±500 uV maximum offset at VCM = 12 V when specifying minimum measurable current.
合规信息
RoHS compliant and lead-free per distributor listings (DigiKey, LCSC). AEC-Q100 applies to the Q1 family variants (e.g., INA2181A1QDGSRQ1), not to this standard part. REACH and halogen-free status not stated in retrieved data.
