Allegro A81415 PMIC Integrates Wheel-Speed Decoding for Automotive Safety
Allegro MicroSystems has introduced the A81415 automotive power management IC, a single device combining a wheel-speed sensor interface, multi-rail power management, and functional safety features. Designed for electromechanical braking systems, the A81415 aims to simplify design and enhance safety in critical automotive applications.
The A81415 is described as the industry's first ASIL-D safety PMIC to integrate a wheel-speed sensor interface. Developed with ASIL D capability and qualified to AEC-Q100 Grade 0, it is built for operation in demanding, safety-critical automotive environments. This integration eliminates the need for a separate wheel-speed decoder IC and its associated analog circuitry, streamlining the braking control loop and reducing the processing load on the vehicle's microcontroller.
Its on-chip wheel-speed sensor interface is capable of decoding standard two-level, pulse-width modulation, three-level AK, and high-resolution AK protocols. The decoded wheel-speed information is then efficiently transferred to the vehicle's microcontroller via an SPI connection. This consolidation can eliminate up to nine external components, potentially reducing semiconductor bill-of-materials costs by up to $4 per vehicle and freeing over 50% of the associated PCB area.
The power architecture of the A81415 includes a synchronous buck-boost preregulator and five low-dropout linear regulators, all within a single-inductor design that requires no external power switches or diodes. This enables the device to supply multiple control and sensing circuits within an electromechanical brake module. It supports an operating input range of 3.2V to 36V, with a maximum input voltage of 40V, and features robust functional safety elements like foldback short-circuit protection, dual watchdogs, rail monitoring, fault handling, and SPI diagnostics.
Specifications
| Product | Function | Input Voltage Range | Safety Rating | Key Differentiators | Target Applications |
|---|---|---|---|---|---|
| A81415 | Automotive PMIC with Integrated Wheel-Speed Sensor Interface | 3.2V to 36V (40V max) | ASIL-D, AEC-Q100 Grade 0 | First ASIL-D PMIC with integrated wheel-speed sensor interface, single-inductor design, 5 LDOs | Electromechanical braking systems, 12V and 48V vehicle systems |
Key Features
- Integrated wheel-speed sensor interface
- ASIL-D functional safety capability
- AEC-Q100 Grade 0 qualified
- Synchronous buck-boost preregulator
- Five low-dropout linear regulators
- Single-inductor design (no external switches/diodes)
- Decodes two-level, PWM, three-level AK, and high-resolution AK protocols
- SPI interface for wheel-speed data transfer
- Foldback short-circuit protection
- Dual watchdogs, rail monitoring, fault handling, SPI diagnostics
- Low-noise power rails for TMR angle sensors
- Reduces BOM costs and PCB area
Applications
- Electromechanical braking systems
- 12V vehicle braking modules
- 48V electromechanical braking corner modules (with APM81815)
- Wheel-speed sensing
- Motor commutation feedback
- Clamping-force measurement
- Brake caliper electronics
- Safety-critical automotive systems
