Hall-effect Switch Saves Power, Touted as World’s Smallest
Thu, 04/14/2011 - 12:52pm
Diodes Incorporated has released what it asserts is the world’s smallest dual output omnipolar Hall effect switch IC, designed for open/close detection in portable, battery-powered products including cell phones and notebook PCs. The dual output AH1891 is optimized for operation over the supply voltage range 1.8 V to 3.3 V and offers a sleep function, assuring an average current consumption of 7 µA. Provided in an 0.8mm x 0.8mm CSP package, the IC is some 13 times smaller than common three-leaded TSOT packaged alternatives, according to the company, and the IC’s profile measures less than 0.5 mm. 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.