Diodes Incorporated’s World’s Smallest Hall Effect Switch Saves Power As Well As Space

The dual output AH1891 is optimized for operation over the supply voltage range
1.8V to 3.3V and offers a sleep function, assuring an average current consumption of only 7µA.

Provided in an 0.8mm x 0.8mm CSP package, the IC is some 13 times smaller than common 3-leaded TSOT packaged alternatives and is significantly smaller than other DFN and SOT553 packaged parts. The AH1891’s PCB space saving advantage is also complemented by a reduction in off-board height, with the IC’s profile measuring less than 0.5mm. In addition, the IC’s integrated pull-up resistors help simplify the external applications circuit.


Being an omnipolar (north and south pole operated) and dual output device, the AH1891 provides the design flexibility to suit a variety of low power circuit architectures. When a magnetic flux density is detected and exceeds the IC’s operating point, output 1 is pulled low while output 2 is inverted high, enabling different logic systems to be accommodated. Output states are held until magnetic flux density is lower than the IC’s release point.


With operating and release points optimized and stable over the temperature range -40ºC to 85ºC, the AH1891 is immune to the possibility of early or late switching effects. The IC also offers good immunity to RF noise and other circuit stresses.