INA381A1IDSGR - 26V 350kHz Current Sense Amp w/ Comparator | TI
N.º da peça: INA381A1IDSGR ✓ Ativo| Qtd. | Preço unitário | Total |
|---|---|---|
| 1 | $0.9 | $0,90 |
| 10 | $0.78 | $7,80 |
| 100 | $0.62 | $62,00 |
| 500 | $0.49 | $245,00 |
| 1.000 | $0.41 | $410,00 |
| 3.000 | $0.34 | $1.020,00 |
INA381A1IDSGR Visão geral
A current sense amplifier (also called a current-shunt monitor) is a type of analog signal conditioner that measures the small differential voltage developed across an external shunt resistor in the path of a load current. The output voltage is proportional to load current, enabling the system controller to monitor power, perform closed-loop current control, or trigger protection events. The INA381 sits in the hierarchy: current-sense amplifier -> analog amplifier -> signal chain IC -> semiconductor. The integrated comparator in the INA381 lets the same device assert an ALERT output when current exceeds a user-defined threshold, eliminating a separate comparator IC and shrinking the BOM in motor drive, hot-swap, and power-supply protection circuits.
Key features of the INA381A1 include a 26 V common-mode range that comfortably covers 12 V and 24 V industrial buses, a 350 kHz small-signal bandwidth for fast transient response, low offset, and a propagation delay on the comparator output suitable for sub-microsecond overcurrent reaction. The amplifier supports a fixed gain (variant A1 = 20 V/V) that sets the conversion from shunt voltage to output voltage. The internal 1.2V comparator reference and open-drain ALERT output allow direct wire-OR with other system flags. The 8-pin WSON (DSG) 2x2 mm package is 24-pin, leadless, and surface-mountable, suiting dense PCB layouts.
The INA381 uses a chopper-stabilized input stage and a bipolar process technology that deliver low input offset voltage and a low quiescent current. Designers can route the high-side shunt to the inputs while the comparator simultaneously watches the output against the 1.2V threshold. This eliminates timing skew between the analog measurement path and the digital protection path - a common source of nuisance tripping in discrete implementations.
Typical applications include motor-drive overcurrent protection, solenoid and valve current monitoring, battery-pack current monitoring, hot-swap / eFuse circuits, USB and power-distribution load switches, and industrial 24V field-side monitoring. Compared with discrete op-amp + comparator designs, the INA381 reduces board area, BOM count, and propagation-delay variability between the measurement and the protection paths.
When designing with this device, choose the shunt value so the full-scale shunt voltage is comfortably below the input common-mode and linear range, and set the comparator threshold via a resistor divider on the 1.2V reference pin. Place a 0.1 uF supply bypass capacitor close to the VDD pin to keep the chopper clock away from sensitive traces.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
Alternativas drop-in para INA381A1IDSGR — mesmo encapsulamento, compatível pino a pino. Peças de encapsulamento diferente que exigem retrabalho na PCB são excluídas.
Ferramenta de comparação rápida — selecione peças alternativas para comparação lado a lado:
INA381A2IDSGR
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
INA381A3IDSGR
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
INA381A4IDSGR
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
INA381A1QDGSRQ1
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
INA381A1IDSGT
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
INA381A1IDSGR Classificações máximas e características elétricas
| Função | Current sense amplifier with integrated over-current comparator |
| Common-Mode Input Range | 26 V (max) |
| Small-Signal Bandwidth | 350 kHz |
| Supply Voltage Range (VDD) | 2.7 V to 5.5 V |
| Fixed Gain (A1 variant) | 20 V/V |
| Comparator Reference | 1.2 V (internal) |
| Comparator Output | Open-drain ALERT |
| Sensing Topology | High-side or low-side |
| Faixa de temperatura de operação | -40 C to +125 C |
| Encapsulamento | WSON-8 (DSG) 2x2 mm |
| Tipo de montagem | Surface Mount |
| Nível MSL | 2 (168 hours) |
| Status RoHS | Compliant |
| Lead-Free | Yes |
| Número de pinos | 8 |
Configuração de pinos do INA381A1IDSGR
| Pino 1 | IN+ — Non-inverting shunt input (high-side or low-side connection) |
| Pino 2 | IN- — Inverting shunt input |
| Pino 3 | GND — Ground reference |
| Pino 4 | OUT — Amplifier output (proportional to load current) |
| Pino 5 | ALERT — Open-drain comparator output |
| Pino 6 | REF — Comparator threshold reference input (internal 1.2V) |
| Pino 7 | VDD — Supply voltage (2.7 V to 5.5 V) |
| Pino 8 | NC — Not connected (per datasheet) |
Aplicações típicas
INA381A1IDSGR é adequado para 7 aplicaçãos: Motor Drive Overcurrent Protection, Solenoid and Valve Current Monitoring, Battery Pack Current Monitoring, Hot-Swap and eFuse Circuits, USB and Power-Distribution Load Switches, Industrial 24V Field-Side Monitoring, Power Supply Overcurrent Protection.
Motor Drive Overcurrent Protection
The INA381A1IDSGR fits motor-drive overcurrent protection because its 26 V common-mode range covers 12 V and 24 V bus rails while the integrated comparator asserts ALERT in microseconds when phase current exceeds a threshold. With a 20 V/V fixed gain, the part amplifies a 50 mV shunt drop to a 1 V output signal that the comparator can compare against the internal 1.2 V reference after resistor-divider scaling. Placed on the high-side of the H-bridge, the device monitors the DC bus return current without the ground-shift errors of low-side sensing, and the open-drain ALERT pin wires directly to the MCU fault input - eliminating the discrete op-amp + comparator BOM.
Recomendado
Solenoid and Valve Current Monitoring
The INA381A1IDSGR is well suited to solenoid and proportional-valve current monitoring because its 350 kHz bandwidth tracks PWM-solenoid current ripple without lag, while the integrated comparator can assert a stall or short-circuit fault within microseconds. A 20 mOhm shunt produces 20 mV per amp; with the 20 V/V fixed gain this becomes 400 mV per amp at the OUTP pin, comfortably resolved by a 12-bit ADC. The 26 V common-mode window covers 24 V valve-supply rails directly, and the open-drain ALERT lets the same MCU pin monitor multiple solenoids via a multiplexer.
Recomendado
Battery Pack Current Monitoring
The INA381A1IDSGR's 26 V common-mode rating covers 1S to 6S Li-ion packs (4.2 V to 25.2 V), and the integrated comparator enables one-chip charge/discharge monitoring without a separate protection IC. Placed in the high-side return path, the part rejects ground-shift noise from high-current pulses while the ALERT pin signals the battery management MCU when current exceeds safe limits. The fixed 20 V/V gain simplifies the coulomb-counting math because the MCU knows the exact V/A ratio without calibration of a discrete op-amp stage.
Recomendado
Hot-Swap and eFuse Circuits
The INA381A1IDSGR is a natural fit for hot-swap and eFuse controllers because the integrated ALERT comparator reacts to inrush current faster than the host MCU polling loop can respond. With a 5 mOhm shunt on a 12 V rail, full load current of 10 A produces only 50 mV across the shunt; the 20 V/V gain produces 1 V, and the comparator trips at the 1.2 V reference threshold when current exceeds roughly 12 A. The 350 kHz bandwidth detects the sub-microsecond current spikes that occur at hot-plug events, protecting downstream DC-DC converters from damage.
Recomendado
USB and Power-Distribution Load Switches
The INA381A1IDSGR enables per-port USB and load-switch current monitoring in a single small WSON-8 package - 2x2 mm - which is critical for dense multi-port hubs and docking stations. The 26 V common-mode range covers USB-PD's 20 V high-voltage bus, while the open-drain ALERT can be wire-ORed across multiple ports to a single MCU interrupt. The 20 V/V gain converts a 10 mV shunt drop (1 A on 10 mOhm) into a 200 mV output that resolves easily on a 10-bit ADC for legacy USB 2.0 current reporting.
Recomendado
Industrial 24V Field-Side Monitoring
The INA381A1IDSGR is designed for industrial 24V field-side current monitoring where PLCs, IO-Link masters, and sensor power rails must be watched for shorts and overloads. The 26 V common-mode input directly accepts 24 V without external resistor dividers, while the integrated ALERT pin can drive a PLC digital input via an optocoupler for galvanic isolation. The 350 kHz bandwidth captures fast transients from inductive loads and switching valves, and the -40 C to +125 C operating range covers outdoor and factory-floor environments.
Recomendado
Power Supply Overcurrent Protection
The INA381A1IDSGR adds a hardware backup overcurrent layer in isolated and non-isolated DC-DC converters, complementing firmware-based protection in digital controllers. With a 10 mOhm output-side shunt, the 20 V/V gain produces 200 mV per amp, so a 6 A threshold equals 1.2 V at the comparator input - directly matching the internal 1.2 V reference. The open-drain ALERT can pull down the converter's enable pin to perform an autonomous latch-off within microseconds of a fault, faster than any MCU-based protection loop can respond.
Recomendado
Resumo dos produtos recomendados
Dados de referência de engenharia para INA381A1IDSGR — comparação, orientação de projeto e informações de conformidade.
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Comparação com alternativas
| Parâmetro | Este produto | INA381A2IDSGR | INA381A3IDSGR | INA381A4IDSGR | INA381A1QDGSRQ1 | INA381A1IDSGT |
|---|---|---|---|---|---|---|
| Package | WSON-8 (DSG) 2x2 mm | WSON-8 (DSG) 2x2 mm - same | WSON-8 (DSG) 2x2 mm - same | WSON-8 (DSG) 2x2 mm - same | WSON-8 (DSG) 2x2 mm - same | WSON-8 (DSG) 2x2 mm - same |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Fixed Gain (V/V) | 20 | 10 | 100 | 200 | 20 (same) | 20 (same) |
| Common-Mode Range (max) | 26 V | 26 V | 26 V | 26 V | 26 V | 26 V |
| Bandwidth | 350 kHz | 350 kHz | 350 kHz | 350 kHz | 350 kHz | 350 kHz |
| AEC-Q100 Qualified | No | No | No | No | Yes | No |
| Supply Voltage Range | 2.7 V to 5.5 V | 2.7 V to 5.5 V | 2.7 V to 5.5 V | 2.7 V to 5.5 V | 2.7 V to 5.5 V | 2.7 V to 5.5 V |
| Comparator + 1.2V Reference | Yes | Yes | Yes | Yes | Yes | Yes |
| Operating Temperature Range | -40 C to +125 C | -40 C to +125 C | -40 C to +125 C | -40 C to +125 C | -40 C to +125 C (automotive) | -40 C to +125 C |
Principais diferenciais
- Integrated comparator eliminates a discrete protection IC (vs INA200AIDGKR (current-sense amp only, no integrated comparator))
- 26 V common-mode supports 24 V industrial buses directly (vs INA194AIDBVT (older family with lower common-mode range))
- WSON-8 (DSG) 2x2 mm package for dense layouts (vs INA300AIDGSR (similar function in MSOP-10))
Notas de projeto
Estimated: at VDD = 5 V and quiescent current of approximately 350 uA, the INA381A1IDSGT dissipates about 1.75 mW from the supply. A 0.1 uF ceramic bypass capacitor placed within 5 mm of the VDD pin is required to suppress chopper-clock noise from coupling into the sensitive input stage. For high-noise industrial environments, add a 1 uF bulk capacitor in parallel to improve supply rejection at low frequencies.
Route the IN+ and IN- traces as a differential pair directly to the shunt resistor, keeping the loop area under 5 mm squared to reject magnetically coupled transients from adjacent high-current traces. Place the shunt resistor within 10 mm of the input pins to minimize trace-resistance errors and thermal EMF pickup. Use a Kelvin (4-wire) connection to the shunt when currents above 10 A are being measured, to eliminate the IR drop in the high-current trace from corrupting the measurement.
Do not exceed the 26 V absolute maximum on the IN+ and IN- pins - even brief transients above this will permanently damage the part. Use a TVS diode or transient suppressor at the input if the application has inductive kickback (motors, solenoids). The open-drain ALERT output requires an external pull-up resistor (typically 10 kOhm to VDD); leaving it floating will prevent fault detection.
Estimated: with a 20 V/V gain and a 50 mV shunt drop, the OUT pin swings 1 V; at 350 kHz bandwidth the slew rate demand is roughly 1 V / 286 ns = 3.5 V/us, well within the part's capability. However, capacitive loading above 100 pF on the OUT pin can cause peaking; a 10-100 Ohm series resistor at the output can isolate the capacitive load if long PCB traces drive the ADC.
Informações de conformidade
Standard INA381A1IDSGR is industrial grade; for AEC-Q100 automotive qualification, use the INA381A1QDGSRQ1 variant. RoHS and lead-free confirmed per TI product page.
