Diodes, Inc. introduces the smallest Hall-effect switch AH1891
By Christina Nickolas
Designed for open/close detection in portable, battery-powered products including cell phones and notebook PCs, the AH1891 Hall-effect switch measures just 0.8 x 0.8 x 0.5 mm and is offered as the smallest dual-output omnipolar device of its kind. It is claimed to be 13 times smaller than common three-leaded TSOT-packaged alternatives and smaller than other DFN and SOT553 packaged parts.
To support battery-powered equipment the switch has been optimized to operate over the supply range of 1.8 to 3.3 V and offers a sleep function, assuring an average current consumption of only 7 µA. In addition, the IC’s integrated pullup resistors help simplify the external applications circuit.
The outputs of the AH1891 are switched with either a North or South pole of sufficient strength. 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.
Housed in a CSP package, the switch also features an operating temperature of –40° to 85°C and ESD protection of greater than 4 kV in HB mode. ($0.20 ea/10,000 — available now.)
