ACS71240 Integrated Current Sensor

By Allegro MicroSystems, LLC 122

ACS71240 Integrated Current Sensor

 Allegro MicroSystems' 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 µs. 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 3 mm x 3 mm wettable flank QFN package can be used on voltage rails up to 120 VDC and enables the solder joint inspection required in zero PPM automotive applications. The standard footprint SOIC-8 package is UL Certified to 2400 VRMS of isolation and offers a working voltage of 420 VDC or 297 VRMS.

Features and Benefits
  • AEC-Q100 qualified automotive-grade; facilitates system level certification
  • 5 V and 3.3 V operation components are factory-trimmed and optimized for 5 V or 3.3 V operation, providing customers with flexibility throughout the design cycle
  • Differential sensing provides immunity to stray magnetic fields enabling flexible layout and accurate measurements in noisy environments
  • Non-ratiometric output provides immunity in the presence of noisy power supply voltages
  • Accuracy <1.5% (typical) advanced signal path provides improved offset and sensitivity across temperature
  • Low conductor impedance (EX: 0.6 mΩ, LC: 1.2 mΩ) minimizes power losses
  • Dedicated overcurrent fault pin (accuracy 10% max.), factory programmable range (0.5 to 2x IP)
  • On-die dv/dt rejection shield: on-die ground shield provides immunity to dv/dt in switching applications
  • 3 mm x 3 mm wettable flank package and SOIC-8 small packages are ideal for space-constrained applications; the wettable flank allows for solder joint visual inspection (ideal for auto applications); this requires less PCB space compared to a shunt/op amp solution
  • EX: 120 V isolation, LC: 2.4 kV isolation QFN is ideal for 12 V and 48 V applications while SOIC-8 provides 420 Vpk and 297 VRMS working voltages


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