User-programmable Hall-effect linear sensors in miniature packages

The new A1380 family of devices further enhances Allegro's already diverse portfolio of position detecting sensors by providing users with the accuracy and flexibility of fully programmable linear devices without the penalty of a larger package and higher cost.

The flexibility and accuracy of the new sensors is accomplished in two ways.
First, the one-time programmable, read-only memory (OTP-ROM) contained in these analogue sensors allows users to optimise the device in a finished sensor assembly. This optimisation serves to reduce inaccuracies caused by manufacturing tolerances, and simplifies the assembly process. Secondly, the patented dynamic offset cancellation provides extremely low offset and minimal temperature drift.

Through a series of voltage pulses on the output of either of the 3-lead miniature packages, the user is able to carry out fine adjustment of the sensitivity of these devices around one of four predetermined nominal values (2.5 mV/G, 3.1 mV/G, 5.0 mV/G and 7.0 mV/G).

Even greater flexibility can be achieved by adjusting the quiescent output voltage (output without the presence of a magnetic field) and the sensitivity temperature coefficient, as well as setting the output polarity for each device. The temperature coefficient of these devices is designed to compensate for temperature coefficients of typical samarium cobalt (SmCo) magnets.

The A1380 Series will operate over a wide ambient temperature range from -40ºC to +150ºC, and are ideally suited for use in automotive and industrial applications.