Cost-Effective Shunt Alternative Hall-based Current Sensor

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.