Allegro MicroSystems, Inc. (Nasdaq: ALGM) has introduced the A81415, which the company calls the industry’s first ASIL-D-certified power management IC (PMIC) to integrate a wheel-speed sensor interface (WSSI), eliminating up to nine external components from electromechanical braking (EMB) corner-module designs, according to Allegro. The single-chip device pairs a complete safety PMIC architecture with on-chip wheel-speed decoding, targeting the fail-operational power and sensing demands of next-generation brake-by-wire systems. Engineers building EMB corner modules today typically combine a generic safety PMIC with a separate wheel-speed decoder and a cluster of discrete power components — an approach that adds cost, consumes board space, and multiplies potential failure points at the wheel. Allegro says the A81415 collapses that stack into a single part, freeing more than 50% of usable board space at the brake caliper.
Highlights
- Eliminates up to nine external components, saving an estimated $4 in semiconductor bill-of-materials (BOM) cost per vehicle, according to Allegro
- Frees more than 50% of usable circuit board space at the brake caliper, the company says
- On-chip WSSI decodes 2-level, 2-level Pulse Width Modulation (PWM), and 3-level AK wheel-speed protocols, in both standard and high-resolution modes, without a separate decoder IC
- ASIL-D and AEC-Q100 qualified, with dual watchdogs and built-in fault handling on Allegro’s automotive grade-0 process
One Chip Replaces a Corner-Module Stack
Brake-by-wire is becoming a foundational chassis technology in software-defined vehicles, and the physical act of stopping still happens at the wheel — a location that demands fail-operational power and accurate wheel-speed data in tight, vibration-prone, thermally stressed spaces. OEMs are already scaling electromechanical braking into production; ZF secured a brake-by-wire supply contract spanning nearly 5 million vehicles covering its own EMB system. Allegro’s approach targets the same shift from the supplier side, folding wheel-speed sensing directly into the power chip rather than pairing it with a standalone decoder.
Because the physical layer of the wheel-speed signal is handled internally by the PMIC and the decoded data is shared over a Serial Peripheral Interface (SPI), Allegro says the design trims latency in the safety-critical control loop and frees microcontroller bandwidth for faster braking response.
Power and Sensing Built as One System
The A81415 integrates a buck-boost pre-regulator, five low-dropout (LDO) regulators, and a single-inductor architecture that Allegro says requires no external switches or diodes. Its power rails are tuned to run Allegro’s XtremeSense™ tunneling magnetoresistance (TMR) angle sensors, with the goal of keeping the commutation and clamping-force signal chain optimized as one system from wheel to caliper.
The move mirrors a broader semiconductor push into by-wire chassis electronics; Infineon introduced a competing ASIL-D-compliant gate driver IC built for brake-by-wire and steer-by-wire motor control in 2024, targeting similar safety-critical corner-module designs.
A Fast Track From 12V to 48V
Built on Allegro’s automotive grade-0 process and paired with the APM81815 pre-regulator and 48V gate drivers, the A81415 forms what Allegro describes as a complete, fail-operational chipset. The company says the pairing gives Tier 1 suppliers a path to move proven 12V braking architectures to 48V corner modules without a full redesign or bulky external transient protection.
“Intelligent chassis systems demand that sensing and power electronics at the wheel act as one,” said Peter Wells, Business Line Director, High Performance Power at Allegro MicroSystems. “Allegro combined our wheel-speed sensing leadership and high-reliability power management expertise into our new PMIC to give our customers a simpler, safer and highly scalable foundation for modern vehicle brake-by-wire.”
Availability
Allegro introduced the A81415 last week and is showing it at the Allegro booth (N5.300) at electronica Shanghai. Samples and evaluation support are available through the company.
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