INA381A3IDSGR

Current Sense Amplifier with Integrated Comparator

The INA381A3IDSGR is a current sense amplifier with integrated comparator from Texas Instruments. View the full INA381A3IDSGR datasheet below including key specifications, pinout, electrical characteristics, absolute maximum ratings.

Manufacturer

Texas Instruments

Key Specifications

Parameter	Value
Accuracy	±1%
Function	Current Sense
Mounting Type	Surface Mount
Operating Temperature	-40°C ~ 125°C (TA)
Package / Case	8-WFDFN Exposed Pad
Packaging	MouseReel
Sensing Method	High/Low-Side
Standard Pack Qty	3000
Supplier Device Package	8-WSON (2x2)
Supplier Device Package	8-WSON (2x2)
Input Voltage Range	0V ~ 26V

Overview

Part: INA381 — Texas Instruments

Type: High-Speed, Current Sense Amplifier With Integrated Comparator

Description: The INA381 is a 26-V common-mode current-sensing amplifier with an integrated high-speed comparator, capable of detecting overcurrent conditions by measuring voltage across a shunt resistor and comparing it to a user-defined threshold.

Operating Conditions:

Supply voltage: 2.7 V to 5.5 V
Operating temperature: -40 to +125 °C
Common-mode input voltage: -0.2 V to 26 V

Absolute Maximum Ratings:

Max supply voltage: 6 V
Max junction temperature: 150 °C
Max storage temperature: 150 °C

Key Specs:

Common-mode input range: -0.2 V to +26 V
Offset voltage (VCM = 12 V, TA = 25°C): ±500 μV (maximum)
Offset voltage (VCM = 0 V, TA = 25°C): ±150 μV (maximum)
Offset voltage drift: 1 μV/°C (maximum)
Gain error (TA = 25°C): ±1% (maximum)
Gain error drift: 20 ppm/°C (maximum)
Quiescent current (VSENSE = 10 mV, TA = +25°C): 250 μA (typical), 350 μA (maximum)
Comparator propagation delay (CMPIN overdrive = 20 mV): 0.4 μs (typical), 1 μs (maximum)
Comparator hysteresis: 50 mV

Features:

High accuracy amplifier with low offset voltage and drift
Available amplifier gains: 20 V/V, 50 V/V, 100 V/V, 200 V/V
Open-drain comparator with 50 mV hysteresis
Alert threshold set through external reference voltage
Supports transparent and latching comparator modes
Fast alert response time

Applications:

Merchant network and server PSU
Merchant DC/DC
DC-input BLDC motor drive
Cordless power tool
Headsets, headphones and earbuds

Package:

VSSOP (10) - 3.00 mm × 3.00 mm
WSON (8) - 2.00 mm × 2.00 mm

Features

1 · Common-mode input range: -0.2 V to +26 V
High accuracy amplifier:
-Offset voltage at TA = 25°C
-500 μV (maximum) at VCM = 12 V
-150 μV (maximum) at VCM = 0 V
-Offset voltage drift: 1 μV/°C (maximum)
-Gain error: 1% (maximum) at 25°C
-Gain error drift: 20 ppm/°C (maximum)
Available amplifier gains:
Open-drain comparator:
-Hysteresis: 50 mV
-Propagation delay: 400 ns (typ)
-Alert threshold set through external reference voltage
-Supports transparent and latching modes
Packages: VSSOP-10 and WSON-8
INA381A1: 20 V/V
INA381A2: 50 V/V
INA381A3: 100 V/V
INA381A4: 200 V/V

Applications

Merchant network and server PSU
Merchant DC/DC
DC-input BLDC motor drive
Cordless power tool
Headsets, headphones and earbuds

Pin Configuration

Pin	Name	Type	Description
1	IN+	Analog input	Connect this pin to the supply side of the shunt resistor
2	VS+	Supply	Power supply: 2.7 V to 5.5 V
3	ALERT	Digital output	Overlimit alert, active low, open-drain output
4	RESET	Digital input	Transparent or latch mode selection input. See the Alert Modes section for a detailed description on pin connections.
5	CMPREF	Analog input	Input reference to the comparator
6	CMPIN	Analog input	Signal input to the comparator
7	VOUT	Analog output	Current-sense amplifier output voltage
8	IN-	Analog input	Connect this pin to the load side of the shunt resistor
Thermal Pad	Thermal Pad	-	Ground reference for the device that is also the thermal pad used to conduct heat from the device. Tie this pad externally to ground.

Electrical Characteristics

at TA = 25°C, VSENSE = VIN+ - VIN= 10 mV, VS = 5 V, VIN+ = 12 V, and CMPREF = 2 V (unless otherwise noted)

	PARAMETER	TEST CONDITIONS	MIN	TYP	MAX	UNIT
INPUT
CMRR	Common-mode rejection ratio, RTI (1)	V IN+ = 0 V to 26 V, T A = -40°C to +125°C	84	100		dB
V	Offset voltage, RTI (1)	V IN+ = 12 V, V IN- = 12 V		±100	±500
OS		V IN+ = 0 V, V IN- = 0 V		±25	±150	μ V
dV OS /dT	Offset voltage drift, RTI (1)	T A = -40°C to +125°C		0.1	1	μ V/°C
PSRR	Power-supply rejection ratio	V S = 2.7 V to 5.5 V, T A = -40°C to +125°C		±8	±40	μ V/V
I B	Input bias current	V SENSE = 0 mV, I B+ , I B-		80		μ A
I OS	Input offset current	V SENSE = 0 mV		±0.05		μ A
OUTPUT	Gain	INA381A1		20
G		INA381A2		50
G		INA381A3		100		V/V
G		INA381A4		200
E G	Gain error	VOUT = 0.5 V to V S - 0.5 V		±0.1%	±1%
	Gain error drift Nonlinearity error	T A = -40°C to +125°C V OUT = 0.5 V to V S - 0.5 V		1.5 ±0.01%	20	ppm/°C
	Maximum capacitive load	No sustained oscillation		1		nF
VOLTAGE	OUTPUT
	Swing to V S power-supply rail	R L = 10 k Ω to GND, T A = -40°C to +125°C		V S - 0.02	V S - 0.05	V
	Swing to GND (2)	R L = 10 k Ω to GND, T A = -40°C to +125°C		V GND + 0.0005	V GND + 0.005	V
FREQUENCY RESPONSE	FREQUENCY RESPONSE
BW	Bandwidth	INA381A1 INA381A2 INA381A3 INA381A4		350 210 150 105		kHz kHz kHz kHz
SR	Slew rate			2		V/μs
NOISE	Voltage noise density			40		nV/ √ Hz
COMPARATOR
t p	Propagation delay time, comparator only	CMPIN Input overdrive = 20 mV		0.4	1	μs
	Large-signal propagation delay, comparator only	CMPIN step = 0.5 V to 4.5, V CMPREF = 4 V		0.4	2	μs
	Small-signal total alert propogation delay, comparator and amplifier	Input overdrive = 1 mV		2	5	μs
	Slew rate limited total alert propagation delay, comparator and amplifier	V OUT = 0.5 V to 4.5, V CMPREF = 4 V		3	10	μs
V OS	Comparator offset voltage			±1	±5	mV
HYS	Hysteresis			50		mV
V IH	High-level input voltage		1.4		6	V
V IL	Low-level input voltage		0		0.4	V
V OL	Alert low-level output voltage	I OL = 3 mA		70	300	mV
	ALERT pin leakage input current	V OH = 3.3 V		0.1	1	μ A
	Digital leakage input current	0 ≤ V IN ≤ V S		1		μ A
POWER	SUPPLY
		V SENSE = 10 mV, T A = +25°C		250	350	μ A
I Q	Quiescent current	T A = -40°C to +125°C			450

Absolute Maximum Ratings

over operating free-air temperature range (unless otherwise noted) (1)

			MIN	MAX	UNIT
V S	Supply voltage	Supply voltage		6	V
V IN+ ,V IN-	Analog inputs (IN+, IN-)	Differential (V IN+ ) - (V IN- ) (2)	-26	26	V
V IN+ ,V IN-	Analog inputs (IN+, IN-)	Common-mode (3)	GND - 0.3	26	V
V I	Analog input	CMPIN	GND - 0.3	(V S ) + 0.3	V
V I	Analog input	CMPREF	GND - 0.3	(V S ) + 0.3	V
V O	Analog output	OUT	GND - 0.3	(V S ) + 0.3	V
	Digital input	RESET	GND - 0.3	(V S ) + 0.3	V
	Digital output	ALERT	GND - 0.3	6	V
T J	Junction temperature	Junction temperature		150	°C
T stg	Storage temperature	Storage temperature	-65	150	°C

Recommended Operating Conditions

over operating free-air temperature range (unless otherwise noted)

		MIN	NOM	MAX	UNIT
V CM	Common-mode input voltage	-0.2	12	26	V
V S	Operating supply voltage	2.7	5	5.5	V
T A	Operating free-air temperature	-40		125	°C

Thermal Information

		INA381	INA381
THERMAL METRIC (1)	THERMAL METRIC (1)	DGS (VSSOP)	DSG (WSON)
		10 PINS	8 PINS
R θ JA	Junction-to-ambient thermal resistance	188.6	77
R θ JC(top)	Junction-to-case (top) thermal resistance	78.1	96.5
R θ JB	Junction-to-board thermal resistance	111.0	43.4
Ψ JT	Junction-to-top characterization parameter	17.5	5.4
Ψ JB	Junction-to-board characterization parameter	109.2	43.6
R θ JC(bot)	Junction-to-case (bottom) thermal resistance	N/A	18.8

Typical Application

Related Variants

The following components are covered by the same datasheet.

Part Number	Manufacturer	Package
INA381	Texas Instruments	—
INA381A1	Texas Instruments	WSON-8
INA381A2	Texas Instruments	WSON-8
INA381A3	Texas Instruments	WSON-8
INA381A3IDGSR	Texas Instruments	—
INA381A3IDGSR.B	Texas Instruments	—
INA381A3IDGST	Texas Instruments	—
INA381A3IDSGR.B	Texas Instruments	—
INA381A3IDSGT	Texas Instruments	VSSOP-10
INA381A4	Texas Instruments	WSON-8

Data on this page is extracted from publicly available manufacturer datasheets using automated tools including AI. It may contain errors or omissions. Always verify specifications against the official manufacturer datasheet before making design or purchasing decisions. See our Terms of Service. Rights holders can submit a takedown request.

Get structured datasheet data via API

Get started free