Cost-Effective Shunt Alternative Hall-based Current Sensor


Allegro EX 12 Package


Top Features


The ACS71240 family of automotive AEC-Q100 qualified, monolithic Hall effect current sensor ICs offers next generation improvements over the popular Allegro ACS711 predecessor family of Current Sensor ICs. These improvements include output signal immunity to stray magnetic fields (created by adjacent motors or current carrying wires), improved output signal accuracy (<+/-1.5% typical) and output signal immunity to noisy supply voltage rails. The device also has a dedicated fast Overcurrent Fault output that has a typical response time of 1.5 us. This fast fault output provides a simple means of detecting short circuit events that will prevent MOSFET or IGBT damage in inverter, motor or other switching power electronics applications.

The ACS71240 is offered in two very small form factor package options, each providing different levels of galvanic isolation. The tiny 3mm x 3mm, wettable flank QFN package can be used on voltage rails up to 120VDC and enables solder joint inspection required in zero PPM automotive applications. The standard footprint SOIC8 package is UL certified to 2400VRMS of isolation and offers a working voltage of 420VDC or 297VRMS.

The ACS71240 family is designed to replace shunt resistors, operational amplifiers, current transformers and voltage isolators in applications that require small form factor, monolithic sensor solutions. These fully integrated solutions reduce the overall cost of current sensing by eliminating discrete components that demand printed circuit board area. The sensors are offered for use on 5V or 3.3V power supplies.

  • AEC-Q100 qualified
  • Differential Hall sensing rejects common-mode stray magnetic fields
  • Overcurrent FAULT with a Factory Programmable trip range of 50% to 200% of full-scale current
  • Non-Ratiometric output provides immunity to noisy supplies
  • Galvanically Isolated:
    • QFN package: 120VDC working voltage
    • SOIC8 package: UL certified to 2400VRMS, working voltage of 420VDC or 297VRMS
  • Reduced Power Loss:
    • 0.6 mΩ internal conductor resistance on QFN package
    • 1.2 mΩ internal conductor resistance on SOIC8 package
  • Integrated shield virtually eliminates capacitive coupling from current conductor to die, greatly suppressing output noise due to high dv/dt transients
  • Output voltage proportional to AC or DC current
  • High-bandwidth 120 kHz analog output for faster response times in control applications
  • Factory-trimmed sensitivity and quiescent output voltage for improved accuracy
  • 3.3 and 5 V single supply operation
  • Small footprint, low-profile QFN and SOIC8 packages suitable for space-constrained applications

Part Number Specifications and Availability

Documentation and Resources


Design Tools