ACS712 Hall-effect current sensor connection guide
ACS712 Hall-effect current sensor LC SOIC-8 wiring guide with power, signal assignments, and bench checks.
LC SOIC-8
8 contacts Current package±5 A optimized range, 185 mV/A typical at 5 V and 25 °C.
Measure the zero-current output
RequiredPower the signal side from 5 V. Leave the primary path open for the zero reading.
- 5 V
- VCC (8)
- C1.1
- Signal return
- GND (5)
- C1.2
- CF.2
- Voltmeter common
- Bandwidth setting
- FILTER (6)
- CF.1
- Measured output
- VIOUT (7)
- Voltmeter positive
Bench checks
- Read VIOUT relative to GND on a high-impedance meter. A healthy nominal unit sits near 2.5 V at zero current.
Allegro ACS712-DS Rev. 22, typical application and zero-current characteristics
Connection scenarios
Measure a known DC current
Use an independent, current-limited 5 V source for the primary circuit. A 10 Ω, 5 W resistor limits its current to approximately 0.5 A.
- 5 V
- VCC (8)
- C1.1
- Signal return
- GND (5)
- C1.2
- CF.2
- Voltmeter common
- Bandwidth setting
- FILTER (6)
- CF.1
- Measured output
- VIOUT (7)
- Voltmeter positive
- Primary supply
- Primary load
- Primary return
- Primary source negative
- RL.2
Bench checks
- Measure voltage across RL and divide by its measured resistance to obtain the reference current.
- Subtract the zero reading. At 0.5 A the expected change is about +92.5, +50 or +33 mV for 05B, 20A or 30A respectively.
Allegro ACS712-DS Rev. 22, typical application and sensitivity tables. The bench load is chosen for this test.
LC SOIC-8 wiring map
1 · IP+
First lead of the internally common positive current terminal. Join to pin 2.
Models and documents
The LC-package sensing ranges share one terminal map. Match the exact suffix before converting voltage to amperes.
- ACS712ELCTR-05B-T
- ±5 A optimized range, 185 mV/A typical at 5 V and 25 °C.
- ACS712ELCTR-20A-T
- ±20 A optimized range, 100 mV/A typical at 5 V and 25 °C.
- ACS712ELCTR-30A-T
- ±30 A optimized range, 66 mV/A typical at 5 V and 25 °C.
- ACS712ELCTR-20A-S
- ±20 A optimized range, 100 mV/A typical at 5 V and 25 °C.
- ACS712ELCTR-30A-S
- ±30 A optimized range, 66 mV/A typical at 5 V and 25 °C.
- Allegro ACS712-DS Rev. 22· Selection guide, package drawing, terminal functions and sensitivity tables.
- Source register· Document revisions, applicable order codes, consulted sections and available file checksums.