Allegro® introduces a high precision, programmable two-wire Hall-effect linear sensor with a pulse width modulated (PWM) output. This is the first linear Hall-effect sensor from Allegro to include a voltage regulator, which allows the device to be powered directly from a battery. The duty cycle of the PWM output signal is proportional to an applied magnetic field. Allegro's A1354 device converts an analog signal from its internal Hall sensor element to a digitally encoded PWM output signal. The coupled noise immunity of the digitally encoded PWM output is far superior to the noise immunity of an analog output signal. This new device is targeted at both the automotive and industrial sectors.
The BiCMOS, monolithic circuit inside of the A1354 integrates a Hall element, precision temperature-compensating circuitry to reduce the intrinsic sensitivity and offset drift of the Hall element, a small-signal high-gain amplifier, proprietary dynamic offset cancellation circuits, and PWM conversion circuitry. The dynamic offset cancellation circuits reduce the residual offset voltage of the Hall element. Hall element offset is normally caused by device over molding, temperature dependencies, and thermal stress. The high frequency offset cancellation (chopping) clock allows for a greater sampling rate, which increases the accuracy of the output signal and results in faster signal processing capability.
The A1354 sensor is provided in a lead (Pb) free 4-pin single inline package (KT suffix), with 100% matte tin leadframe plating. It is priced at $1.43 in quantities of 1,000 and has a 12-14 week typical lead-time to market.