By Broadcom Limited 118


Broadcom’s ACHS-712x product series is a fully integrated Hall effect-based isolated linear current sensor device family designed for AC or DC current sensing in industrial, commercial and communications systems. The ±10 A rated ACHS-7121, ±20 A rated ACHS-7122, ±30 A rated ACHS-7123, ±40 A rated ACHS-7124, and ±50 A rated ACHS-7125 consists of a precise, low-offset, linear Hall circuit with a copper conduction path located near the surface of the die. Applied current flowing through this copper conduction path generates a magnetic field that the Hall IC converts into a proportional voltage. Device accuracy is optimized through the proximity of the magnetic signal to the differential Hall transducers.

A precise, proportional voltage is provided by the low-offset, chopper-stabilized CMOS Hall IC, which is programmed for accuracy after packaging. The output of the device has a positive slope (>VOUT(Q)) when an increasing current flows through the primary copper conduction path (from pins 1 and 2 to pins 3 and 4), which is the path used for current sampling.

The internal resistance of this conductive path is 0.7 mΩ typical, providing low power loss. The terminals of the conductive path are electrically isolated from the signal leads (pins 5 through 8). This performance is delivered in a compact, surface mountable, SO-8 package that meets worldwide regulatory safety standards.

Features and Benefits
  • Wide operating temperature: -40ºC to +110ºC
  • Device bandwidth is set via FILTER pin:
    • 80 kHz typ. bandwidth with 1 nF filter capacitor
  • Primary conductor resistance: 0.7 mΩ typ.
  • Sensing current range: ±10 A, ±20 A, ±30 A, ±40 A, and ±50 A
  • Output sensitivity: 40 mV/A, 50 mV/A, 66 mV/A, 100 mV/A, 185 mV/A
  • Output voltage proportional to AC or DC currents
  • Ratiometric output from supply voltage
  • Extremely stable output offset voltage
  • Factory-trimmed for accuracy
    • Worldwide safety approval: UL; CSA; Isolation voltage 3 kVRMS, 1 minute
  • Small footprint, low-profile SO-8 package
  • >25 kV/μs common-mode transient immunity
  • Typical total output error of ±1.5%
  • Near zero magnetic hysteresis
  • Low-power inverter current sensing
  • Motor phase and rail current sensing
  • Solar inverters
  • Chargers and converters
  • Switching power supplies
  • eBikes


SensingSensorsBroadcom Limited