INA139NA/3K - High-Side Current Shunt Monitor 40V | TI
MPN： INA139NA/3K ✓ 啟用中INA139NA/3K 概覽
A current shunt monitor (also called a current sense amplifier) is an analog IC that senses the small differential voltage across a series shunt and converts it to a ground-referenced output current, which an external resistor converts back to a voltage for ADCs or comparators. Within the power-management IC hierarchy, it sits between discrete op-amp sensing circuits and fully integrated digital power monitors, offering the simplest possible high-side measurement solution.
Key features include complete unipolar high-side current measurement in one tiny package, input common-mode and supply voltages that are fully independent (sense voltage may exceed the supply rail, up to 40V), and a single external resistor that sets the transconductance gain. The 60uA quiescent current suits battery-powered equipment, while the 440kHz bandwidth supports fast transient load monitoring.
Architecturally, the INA139 uses a precision current-mirror front end that forces the shunt differential voltage across an external gain resistor; the resulting current is mirrored to the output pin. This current-output topology allows gain scaling from microamp-per-volt to milliamp-per-volt levels and keeps output impedance high, simplifying filtering and level shifting.
Typical applications include battery chargers, telecom and networking line-current monitoring, power supplies, motor control, and automotive or industrial load monitoring. High-side sensing eliminates ground disturbances and simplifies PCB layout compared to low-side sensing.
Design tip: place the shunt between the power source and the load, choose the output resistor for the desired full-scale voltage, and keep the shunt differential voltage within the 0.5V input range while accounting for output compliance versus supply. Pricing references as of 2026-08-29.
直接替換替代品，適用於 INA139NA/3K — 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： INA139NA/3K （相同外形與佔位） — 差異在於 Gain Setting, Output Type, Package, Quiescent Current, Operating Temperature Range.
INA139NA/3K-Q1
✅ 直接替換聯絡詢價
查看資料表 →INA139AIDBVR
✅ 直接替換 ⚠️ 規格未經驗證📋 參考替代品（不在目錄中）
INA169NA/3K
✅ 直接替換聯絡詢價
查看資料表 →ZXCT1010E5T
✅ 直接替換 ⚠️ 規格未經驗證📋 參考替代品（不在目錄中）
INA139NA/3K 最大額定值與電氣特性
| 功能 | High-side unipolar current shunt monitor |
| Supply Voltage Range | 2.7 V to 40 V |
| Input Common-Mode Voltage Range | 2.7 V to 40 V |
| Bandwidth | 440 kHz |
| 靜態電流 | 60 uA (typ) |
| Gain Setting | Single external resistor (current output) |
| Transconductance | 1000 uA/V (with RL = 1 kohm) |
| Full-Scale Sense Voltage | 0.5 V |
| Number of Channels | 1 |
| 輸出類型 | Analog current output (ground-referenced via RL) |
| 工作溫度 | -40C to +125C |
| 封裝 | SOT-23-5 (DBV), 5 pins |
| 安裝類型 | Surface Mount |
| Packaging | Tape & Reel, 3000 units per reel (/3K) |
| RoHS 狀態 | Compliant |
INA139NA/3K 腳位配置
| 腳位 1 | IN+ — Shunt input, connect to supply side of shunt resistor |
| 腳位 2 | GND — Ground reference |
| 腳位 3 | OUT — Current output; connect external gain resistor RL to ground |
| 腳位 4 | V+ — Power supply, 2.7V to 40V |
| 腳位 5 | IN- — Shunt input, connect to load side of shunt resistor |
典型應用
INA139NA/3K 適用於 6 應用s: Battery Charger Current Monitoring, Telecom -48V Power Rail Monitoring, Industrial 24V Motor and Load Monitoring, Automotive Load-Current Supervision, Power Supply and DC-DC Output Monitoring, Portable and IoT Battery-Powered Devices.
Battery Charger Current Monitoring
The INA139NA/3K is ideal for battery chargers because its 2.7V minimum supply and 60uA quiescent current add negligible drain to the monitored system, while high-side placement keeps the battery ground node undisturbed. Placed above the shunt between the charger and battery pack, its 440kHz bandwidth captures fast charge-current transients during CC/CV transitions. A single gain resistor scales the 1000 uA/V output current to match the charger MCU ADC input range directly.
推薦
Telecom -48V Power Rail Monitoring
Telecom boards monitoring current on -48V distribution need the INA139's fully independent supply and common-mode architecture: the shunt sense node can sit at high absolute voltage (up to 40V) regardless of the 2.7V to 40V device supply. The ground-referenced current output with one resistor feeds line cards or supervisory comparators without level shifting. The SOT-23-5 footprint fits dense ATCA and line-card layouts, and -40C to +125C operation covers outdoor plant equipment.
推薦
Industrial 24V Motor and Load Monitoring
In industrial control, the INA139NA/3K monitors 24V motor drive and actuator currents where its 40V common-mode tolerance provides headroom for inductive kickback and supply transients. The 440kHz bandwidth resolves PWM-related current ripple, enabling load-diagnostics and stall detection in PLC I/O. The single shunt plus single gain resistor bill of materials reduces cost versus integrated digital monitors, and the high-side topology avoids ground-loop errors across long cabinet wiring runs.
推薦
Automotive Load-Current Supervision
For automotive body and powertrain ECUs, the AEC-Q100 qualified INA139NA/3K-Q1 variant provides identical specifications in the same SOT-23-5 package for 12V battery bus current monitoring. High-side sensing detects shorts-to-ground and load faults on lamps, pumps, and actuators without inserting resistance in the chassis ground path. The 40V common-mode rating withstands load-dump-adjacent transients, and the analog output feeds window comparators or the MCU ADC for fused-load diagnostics.
推薦
Power Supply and DC-DC Output Monitoring
Point-of-load and DC-DC converters benefit from INA139 high-side output-current telemetry: place the shunt between the converter output and load, then scale the 1000 uA/V current output with RL to produce a ground-referenced voltage for telemetry ADCs. The 440kHz bandwidth supports peak-current and transient capture during load steps, while 60uA IQ keeps monitoring overhead well inside the converter efficiency budget. The tiny SOT-23-5 fits under or beside inductors on dense power boards.
推薦
Portable and IoT Battery-Powered Devices
Wearables, IoT nodes, and handheld instruments use the INA139NA/3K for fuel-gauge assistance and load profiling, since its 60uA quiescent draw is orders of magnitude below typical system budgets. Operation from a 2.7V supply matches single-cell Li-Ion stacked regulators and 3.3V logic rails. The SOT-23-5 package occupies under 8mm2 of board area, and the analog output can be sampled by a low-power MCU ADC only during measurement windows, further reducing average consumption in duty-cycled systems.
推薦
推薦產品摘要
工程參考資料，適用於 INA139NA/3K — 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 | INA139NA/3K-Q1 | INA139AIDBVR | INA169NA/3K | ZXCT1010E5T |
|---|---|---|---|---|---|
| Package | SOT-23-5 (DBV) | SOT-23-5 (DBV) - same | SOT-23-5 (DBV) - same | SOT-23-5 (DBV) - same | SOT-23-5 - same |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Diodes Incorporated |
| Automotive Grade | No | Yes (AEC-Q100) | No | No | No |
主要差異化特點
- Standard (non-automotive) cost-optimized grade (對比INA139NA/3K-Q1)
- 40V common-mode range (對比INA169NA/3K)
- Higher measurement accuracy option in same footprint (對比INA139AIDBVR)
設計說明
Use a 4-terminal (Kelvin) connection to the shunt resistor: route the IN+ and IN- sense traces directly to the shunt pads, not to shared power traces, to avoid including trace resistance in the measurement. Keep the sense traces short and matched. Place the INA139 within a few millimeters of the shunt, and place the output resistor RL close to the OUT pin with its ground return at the ADC or comparator reference ground.
Size Rsense so maximum load current generates no more than 0.5V differential (the datasheet full-scale input), then verify shunt power dissipation P = I2 x Rsense stays within the resistor rating. Set RL so the full-scale output voltage remains within output compliance relative to the V+ supply per the datasheet compliance graph. Decouple V+ with a 0.1uF ceramic capacitor placed within 2mm of pin 4.
Because the OUT pin is a current output with high impedance, a capacitor across RL sets a low-pass filter: f = 1/(2 x pi x RL x C). For noisy industrial environments, add 1nF to 100nF across RL to band-limit the 440kHz signal path and reject PWM ripple while preserving required transient response. Do not drive long cables directly from OUT without this filter or a buffer.
合規資訊
RoHS compliant per TI product listings. Not AEC-Q100 qualified - use INA139NA/3K-Q1 for automotive. REACH/halogen status not stated in provided data.
