The A1346 is the ideal solution for safety-critical applications. It incorporates full die redundancy with the added benefits of advanced diagnostics. The combination of these two features allow for a higher level of diagnostics without interruption to the application (where diagnostics would otherwise render a die temporarily nonresponsive). This combination also allows the controller to know which die to trust when the output of the die do not agree.
The A1346 device has dual high-precision, programmable Hall-effect linear sensor integrated circuits (IC) with open-drain outputs, for both automotive and nonautomotive applications. The signal paths of the A1346 provides flexibility through external programming that allows the generation of accurate and customized outputs from an input magnetic signal. The A1346 is an especially configurable and robust solution for the most demanding linear field sensor applications.
The BiCMOS, monolithic integrated circuits incorporate on each SoC: 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 linearization circuitry, and advanced diagnostic detection. The A1346 provides an unmatched level of customer reprogrammable options.
A key feature of the A1346 is its ability to produce a highly linear device output for nonlinear input magnetic fields. To achieve this, the device features 16-segment customer programmable linearization, where a unique linearization coefficient factor is applied to each segment. Linearization coefficients are stored in a lookup table in EEPROM.
The A1346 contains two proprietary SENT protocols in addition to SAEJ2716: SSENT and ASENT. Both protocols enable the user to attach up to 4 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 maximize the sensor bandwidth on this single SENT line, minimizing 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 A1346 is available in a surface-mount, lead (Pb) free 14‑pin TSSOP package (LE suffix), with 100% matte-tin leadframe plating.
- Two electrically isolated die in one package for the most safety-critical applications
- In the event of a die failure, self-diagnostics allow the controller to discern which die to continue to trust
- For diagnostics that impact response, these diagnostics can be run on each die while the other is fully operational
- For all features below, these refer to each of the two die in the package
- High-speed analog, A-to-D converter (ADC), and digital architectures, enabling user-selectable bandwidth for speed-sensitive applications
- 4-phase chopper stabilization, which minimizes offset drift across temperature range
- 16-bit, high update rate ADC
- Exceptional stability throughout lifetime and across temperature changes
- Factory-configured using multisegment temperature compensation to give a flat baseline across operating temperature range
- Customer configurability for 1st and 2nd order sensitivity and 1st order offset compensation across temperature range
- Integrated feedback coil compensates for drift throughout product lifetime
- Wide operating flexibility to meet any application:
- Field range from ±40 to ±1800 gauss
- Rail to negative rail offset configurability
- High-precision, full output range high and low clamps
- Integrated linearization allows for flexible output waveform translation and compensation for nonlinear magnetic inputs
- Advanced diagnostic-focused features enabling easier systemlevel ASIL compliance
- Full data path validation through active front-end stimulation with internal magnetic coil; this method validates all relevant transistors for device operation
- Logic Built-In Self Test (LBIST) on-demand to validate the digital subsystem
- Large suite of configurable fault monitors provide system level fault detection, including:
- Overvoltage or undervoltage
- Magnetic Field Out of Range detection
- Broken wire detection
- Flexible output protocols with up to 12-bit resolution and configurable error notifications
- Digital open-drain output allows for flexible output voltage levels
- PWM (Pulse-Width-Modulated) output with diagnostic output mode to identify fault conditions
- SENT (Single Edge Nibble Transmission) compliant output with configurable reporting of error conditions and other diagnostic information
- Proprietary Fast SENT provides increased data rates to support high-bandwidth applications
- Device-shared SENT protocol as SSENT (Sequential SENT) and ASENT (Addressable SENT) allows user to connect up to 4 devices on the same output line for faster communication.
- Enhanced EMC tuning through programmable fall-time
- Integrated EEPROM enables a high level of configurability and product traceability
- Customer-reserved area allows on-board storage of unique lot and date code information
- Robust EEPROM with Single Error Correction and Double Error Detection (SECDED), capability
- Integrated charge pump allows in-application programming without any requirement for high voltages to be supplied to the device during programming
- Allegro Sensor Bias LDO