Firmware/ Embedded Engineer

About the role

We are building an integrated PSU+BBU rack power shelf that combines power conversion and solid-state battery backup into a single platform for hyperscale AI data centers. Unlike a standard server PSU with unidirectional power flow, this system manages bidirectional conversion, real-time battery state management, and seamless mains-to-battery transfer—all within sub-millisecond timing constraints.

As Firmware/Embedded Engineer, you implement the real-time control loops that regulate power delivery, manage the battery charge/discharge path, execute seamless transfer between mains and battery power, and expose the shelf as a fully managed device to the rack's baseboard management controller.

A standard PSU runs a simple control loop on a unidirectional power path. Your system juggles two competing control objectives simultaneously—holding the output rail steady for GPU trays while managing battery current within safe limits—and must execute a flawless handoff between power sources under the most critical conditions (mains failure). The firmware is what makes this an integrated platform rather than two separate boxes. Your work with the power electronics lead forms the technical spine of the entire product.

Responsibilities

• Implement digital compensators for voltage and current regulation loops running at 50-200kHz control rates on a power-oriented DSP/MCU (TI C2000, Microchip dsPIC, or equivalent).
• Design and implement the bidirectional power flow state machine: mains-powered→battery-powered→mains-restored transitions with zero output disturbance and sub-millisecond transfer time.
• Integrate battery charge algorithms (CC-CV profiles, temperature-dependent rate limits, float/maintenance charge modes) developed in collaboration with the battery systems engineer.
• Implement PMBus command set for host communication, enabling the rack BMC to monitor and control the shelf (voltage/current telemetry, SoC/SoH reporting, enable/disable, fault status).
• Develop Redfish/IPMI telemetry reporting for integration with hyperscaler fleet management systems.
• Design fault detection and protection logic: overcurrent, overvoltage, overtemperature, battery undervoltage, and communication loss—with sub-microsecond hardware-assisted trip paths and firmware-managed recovery sequences.
• Build power sequencing and hot-swap control logic for safe insertion/extraction under live bus conditions.
• Develop diagnostics, event logging, and field debug capabilities (black-box flight recorder for fault events).
• Validate control algorithms using hardware-in-the-loop simulation before committing to prototype hardware.
• Support bench bringup and prototype testing alongside the power electronics lead.

Requirements

• 8+ years writing real-time firmware for power converters (not generic embedded systems; you must understand digital control loop theory).
• Proficiency with TI C2000 (strongly preferred), Microchip dsPIC, or equivalent power-oriented DSP/MCU platforms.
• Deep understanding of digital compensator design: pole-zero placement, loop bandwidth, phase margin, and their impact on transient response and stability.
• Hands-on experience with PWM generation, ADC sampling synchronization, and interrupt-driven control loops.
• Experience implementing PMBus or I2C-based power management communication protocols.
• Track record with at least one power converter product through prototype bringup and validation.
• Fluent in C for bare-metal and RTOS environments; comfortable with fixed-point math for real-time control.

Skills

• Prior BMS firmware experience (cell balancing, SoC estimation via EKF or coulomb counting, protection state machines).
• Familiarity with OpenBMC integration and Redfish/IPMI protocols.
• Experience with functional safety standards (IEC 61508 or ISO 26262 from automotive).
• Proficiency with hardware-in-the-loop tools (PLECS RT Box, Typhoon HIL, dSPACE).
• Experience with CAN bus, SPI, or UART-based multi-board communication in power systems.
• Exposure to OCP power shelf communication and management standards.