A1351 Hall Effect Sensor ICs

The BiCMOS, monolithic circuit inside of the A1351 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 A1351 device is a high precision, programmable linear Hall effect sensor IC with a pulse width modulated (PWM) output. The duty cycle (DC) of the PWM output signal is proportional to an applied magnetic field. The A1351 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. A simple RC network can be used to convert the digital PWM signal back to analog signal.

width modulated (PWM) output provides increased noise immunity compared to an analog output