Diodes Incorporated has introduced the world's smallest programmable omnipolar Hall effect switch. The AH1892 is well-suited for proximity and position detection in space-constrained portable and battery-powered products, including tablets, smart phones and camcorders. Provided in the miniature 4-pin 0.7mm x 0.7mm x 0.5mm U-WLB0707-4 package, the micropower AH1892 is seventeen times smaller than the common 3-pin TSOT packaged alternatives.
The package's space-saving advantage is further enhanced by the switch's integrated pull-up resistors, which simplify the external circuit layout and save more PCB space. A simple band select pin enables device sensitivity to be programmed to one of two predefined magnetic sensitivity ranges, allowing the device to be used in multiple applications with different field strengths. Sensitivity can also be adjusted on the fly via an external logic source such as a microcontroller, whereby band can be adjusted with a simple firmware upgrade.
The AH1892's lower operating voltage supply range, from 1.6V through to 3.6V, has been specifically optimized for portable and battery-powered applications; with normal operation consuming an average current of just 4.3µA, the switch ensures battery life is maximized. To help improve product reliability during manufacture and use, the device provides protection against electrostatic discharge to a level of 8kV on supply and output pins.
With Hall switch operating and release points highly stable over the extended temperature range from -40ºC to 85ºC and with a very low temperature coefficient, the AH1892 is immune to the possibility of early or late switching effects. The device's chopper based design also offers high resistance to RF noise and other circuit stresses.
Besides the miniature U-WLB0707-4 package, the AH1892 is also offered in the standard low-profile SOT553 package. A high-sensitivity version of the AH1892 will be made available later in the year will be the AH1894, available in both SOT553 and DFN1216-4 package options. The AH1892 programmable micropower omnipolar Hall effect switch from Diodes Incorporated is priced at $0.20 USD each in 10k piece quantities.