A family of Hall-effect linear sensors offers users the accuracy and flexibility of fully programmable position-detecting sensors without the penalty of a larger package size and higher cost. The devices, from Allegro MicroSystems Inc., come in either a TO-92 (three-lead, single in-line) package or an SOT-23W (three-lead, surface-mount) package.
Two features contribute to the flexibility and accuracy. First, an on-board, one-time programmable, read-only memory lets users optimize the device in a finished sensor assembly. This optimization reduces inaccuracies caused by manufacturing tolerances and simplifies the assembly process. Second, the patented dynamic offset cancellation ensures extremely low offset and minimal temperature drift.
Users can finely adjust the sensitivity of the sensors around one of four predetermined nominal values (2.5 mV/G, 3.1 mV/G, 5.0 mV/G, and 7.0 mV/G) through a series of voltage pulses on the output of either package. Even greater flexibility is available by means of adjusting the quiescent output voltage (the output without the presence of a magnetic field) and the temperature coefficient, as well as by setting the output polarity for each device. The temperature coefficient of this family is designed to compensate for the temperature coefficients of typical samarium-cobalt (SmCo) magnets.
For more information, visit www.allegromicro.com.