The A31102 is an especially configurable and robust solution for the most demanding linear magnetic field sensing applications, including torque sensing in electronic power steering (EPS).
Two key features of the A31102 are the low noise output and capability to provide a highly linear device output even with nonlinear input magnetic fields. To achieve this, each BiCMOS monolithic integrated circuit includes the following: a Hall sensing element, an ultra-low noise front end amplifier, proprietary dynamic offset cancellation circuits, on-chip stress compensation circuitry, a 16-bit analog-to-digital converter (ADC), and a highly flexible digital signal path that includes precision temperature compensating circuitry to reduce the intrinsic sensitivity and offset drift of the Hall element, advanced output linearization circuitry and advanced diagnostic detection features. It also includes on-chip EEPROM for storing all necessary factory- and customer-programmable parameters to correctly configure each device.
The A31102 was developed in accordance with Allegro’s third party certified ISO 26262:2011 compliant development processes, and as such is ideal for safety-critical applications like EPS torqu sensing. The A31102 dual die option (DD) was designed to meet ASIL D requirements and the A31102 single die option was design to meet ASIL B requirements, when integrated and used in conjunction with the appropriate system-level control, in the manner prescribed in the A31102 Safety Manuals. Contact your local Allegro sales representative for more detailed functional safety-related documentation, like the Safety Manual.
The A31102 contains two proprietary SENT protocols in addition to SAEJ2716—SSENT and ASENT. Both protocols enable the user to attach up to four devices on one SENT line to reduce system costs. SSENT allows sequential access to the sensors connected to the same line. SSENT provides a very low overhead method to maximize the sensor bandwidth on this single SENT line, minimizing impact on system performance. ASENT allows direct addressable 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 A31102 is available in a surface-mount, lead (Pb) free 14-pin TSSOP package (LU suffix), with 100% matte-tin leadframe plating.
The A31102 complies with the requirements of EU Directive 2002/95/ EC (RoHS) and 2011/65/ EU (RoHS II), amended by 2015/863/ EU, on the Restriction of the use of certain Hazardous Substances in electrical and electronic equipment.
