Diodes Inc. : AH37xx family of Hall-effect latches gives range of sensitivity and output options


AH37xx latches: wide 3V-28V input-voltage range

The AH37xx family of high-voltage Hall-effect latch ICs introduced by Diodes Incorporated offers a range of magnetic threshold values, enabling it to address motor-control, position-sensing and speed-measuring requirements in a wide variety of applications.

The AH37xx devices may be successfully used for controlling the commutation of brushless DC motors, to measure the speed of rotation in motors, pumps and flow meters, and for contactless position sensing and position indexing.

Suitable for use in both industrial and consumer equipment, the AH37xx family operates from a wide input-voltage range of 3V to 28V, and integrates a reverse-blocking diode, Zener clamps on I/O pins and an output-current limit to help to provide protection from transients and overloads.

An extended temperature specification of -40°C to 125°C and a low temperature coefficient ensure reliable operation at the switching threshold points. The latches’ 6kV ESD capability makes them robust and allows for easier handling during manufacturing.

Users of the AH37xx benefit from the flexibility of various magnetic operation (BOP) and release (BRP) thresholds:
• the AH3772/4 and AH3781/2 provide high sensitivity, with BOP and BRP of 25G/40G and -25G/-40G
• the medium-sensitivity AH3775/6 parts are rated at 70G/110G and -70G/-110G
• the AH3777 is the least sensitive, with a 140G and -140G specification for BOP and BRP`

The designer is also offered a choice of output configurations: the AH377x series has an open drain; the AH378x parts, on the other hand, have an internal pull-up resistor, helping to lower component count and save board space.


  • 10μs power-on time
  • 3.75μs response time
  • High temperature stability
  • High immunity to RF noise


  • Washing machines
  • Dishwashers
  • Fridge-freezers
  • Air conditioners
  • Food processors
  • Power tools
  • Cooling fans
  • Printers
  • Scanners
  • Window blinds