Abstract
Configurable and robust solution for demanding linear field sensor IC applications
Allegro MicroSystems has announced a new high-precision, programmable Hall-effect linear sensor integrated circuit (IC) with an open-drain output, for both automotive and non-automotive applications. The signal path of Allegro’s A1342 provides flexibility through external programming that allows the generation of an accurate and customised output from an input magnetic signal.
This new device is an especially configurable and robust solution for the most demanding linear field sensor IC applications. The BiCMOS, monolithic IC incorporates a Hall sensing 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, advanced output linearisation circuitry, and advanced diagnostics. Allegro’s A1342 provides an unmatched level of customer-programmable options.
A key feature of the A1342 is its ability to produce a highly linear device output for non-linear input magnetic fields. To achieve this, the device features 16-segment customer-programmable linearisation, where a unique linearisation coefficient factor is applied to each segment. Linearisation coefficients are stored in a look-up table in EEPROM.
This new device has two configurable output options: SENT or PWM. In addition to SAEJ2716, the IC includes two additional proprietary SENT options: SSENT and ASENT.
Both protocols enable bus configurations with up to four devices on one SENT line to reduce system costs. SSENT provides sequential access to the sensors connected to the same line. SSENT provides a very low overhead method to maximise the sensor bandwidth on this single SENT line, minimising impact on system performance. ASENT provides random access to all the sensors on the common SENT line.
Both protocols allow individual sensors on the same line to enter diagnostic mode while the other sensors continue to respond to queries, allowing for the highest diagnostic coverage while maintaining 100% availability of the sensor solution.
The A1342 is available in a through-hole, lead (Pb) free 3-pin SIP package (UC suffix), with 100% matt-tin leadframe plating. The UC package includes integrated capacitors for improved ESD performance and to enable PCB-less designs.