A fully integrated Hall-effect linear current sensor in a SOIC-8: current flows through an internal 1.2 milliohm copper path (pins IP+ to IP-) and the on-chip Hall sensor reports it as an analog voltage on VIOUT, with the sensing electronics galvanically isolated from the current path (up to 2.1 kV). The output sits at half-supply (2.5 V at 0 A) and swings proportionally, so it reads bidirectional AC or DC current. Factory-trimmed variants cover plus/minus 5 A (185 mV/A), plus/minus 20 A (100 mV/A), and plus/minus 30 A (66 mV/A). Runs from a single 5 V supply.

Pinout

Pin	Name	Type	Function
1	IP+	passive	Primary current input terminal (positive). Terminals for current being sampled; fused internally. Pins 1 and 2 are tied together to carry the sensed current into the on-die copper conduction path.
2	IP+	passive	Primary current input terminal (positive). Terminals for current being sampled; fused internally. Pins 1 and 2 are tied together to carry the sensed current into the on-die copper conduction path.
3	IP-	passive	Primary current output terminal (negative/return). Terminals for current being sampled; fused internally. Pins 3 and 4 are tied together to carry the sensed current out of the on-die copper conduction path.
4	IP-	passive	Primary current output terminal (negative/return). Terminals for current being sampled; fused internally. Pins 3 and 4 are tied together to carry the sensed current out of the on-die copper conduction path.
5	GND	power_in	Signal ground terminal. Reference ground for VCC and VIOUT on the signal side of the isolation barrier.
6	FILTER	passive	Terminal for external capacitor (CF) that sets output bandwidth. Forms an RC filter with the internal RF(INT) ≈ 1.7 kΩ. Typical value is 1 nF for the default 80 kHz bandwidth.
7	VIOUT	output	Analog output signal. Voltage proportional to the sensed primary current IP, with a quiescent (zero-current) output of VCC × 0.5 (bidirectional variants). Sensitivity ranges from 66 to 185 mV/A depending on the current-range variant.
8	VCC	power_in	Device power supply terminal. 5.0 V nominal (4.5 V min / 5.5 V max). Typical supply current ICC ≈ 10 mA. Decouple with 0.1 µF to GND close to the pin.

Key specifications

Parameter	Value
Type	Hall-effect linear current sensor
Sensing	galvanically isolated (2.1 kV)
Conductor resistance	1.2 mΩ
Output	analog, 2.5 V at 0 A (ratiometric)
Ranges	±5 A / ±20 A / ±30 A
Sensitivity	185 / 100 / 66 mV/A
Supply voltage	5 V
Package	SOIC-8

Ordering variants

ACS712ELCTR-05B-T (±5 A)
ACS712ELCTR-20A-T (±20 A)
ACS712ELCTR-30A-T (±30 A)

CAD (KiCad official)

Symbol: Sensor_Current:ACS712xLCTR-20A
Footprint: Package_SO:SOIC-8_3.9x4.9mm_P1.27mm
3D model: SOIC-8 (KiCad packages3D)

Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

Datasheet: Allegro MicroSystems datasheet (16 pp, sha256 21b345f7a98d3694, retrieved 2026-08-17, tier: manufacturer)
Extractor: ds2sf (Claude). Every pin and dimension is cited to a datasheet page; it refuses to fabricate.
CAD: KiCad official libraries (CC-BY-SA 4.0).

Datasheet PDF