Principal Firmware Engineer – Power Conversion Control

This is a fully remote position, open to applicants in California.

📋 Description

• Develop real-time control loops for four-switch buck-boost power stages and their successor configurations, including multiphase interleaved operation and phase current balancing.

• Take ownership of and manage a portable, MCU-agnostic DC/DC control library, which encompasses compensators, mode arbitration, scheduler and ISR architecture, as well as platform abstraction.

• Create firmware for converter protection, which includes cycle-by-cycle current limiting, overvoltage and undervoltage safeguards, thermal derating, gate-drive fault management, and safe-state transitions.

• Derive models of the plant and design discrete-time compensators for buck, boost, and four-switch buck-boost topologies.

• Implement deterministic C control loops within fixed cycle budgets, utilizing fixed-point or single-precision arithmetic.

• Architect and sustain fast control and slower supervisory ISR tasks with measured jitter and documented worst-case execution times.

• Configure and verify PWM, ADC, comparator, DAC, DMA, trigger timing, dead-time, and hardware-independent protection pathways.

• Implement arbitration for operating modes across various scenarios, including constant current, constant voltage, constant power, current limiting, soft-start, buck-to-boost transitions, phase shedding, and charge/discharge reversal.

• Bring up converter hardware in the laboratory through comprehensive operating-envelope characterization.

• Measure and correlate loop gain, transient response, ripple, efficiency, and thermal derating.

• Develop and maintain simulation and hardware-in-the-loop setups to identify control regressions.

• Write specifications, requirements, and traceable verification evidence for certification reviews.

• Review control and embedded code and actively participate in hardware design reviews.

⛳️ Requirements

• Bachelor’s degree in Electrical Engineering, Computer Engineering, or equivalent demonstrated experience.

• At least six years of experience in developing production embedded firmware in C for resource-constrained real-time systems.

• Direct hands-on experience in closing control loops in firmware for switched-mode power converters.

• Proven ability to specify topology, control mode, switching and sampling frequencies, compensator structure, crossover, and phase margin for validated converter hardware.

• Strong understanding of discrete-time control, including bilinear/Tustin and zero-order-hold mappings, sampling and computational delay, aliasing, and quantization.

• Proficiency with high-resolution PWM, PWM-triggered ADCs, programmable sample instants, analog comparators, DAC fast-fault pathways, and DMA.

• Competence in fixed-point arithmetic, encompassing Q-format scaling, range and overflow analysis, and saturation behavior.

• Ability to substantiate fixed-point versus floating-point decisions based on execution time considerations.

• Experience in deterministic ISR design under strict timing constraints, including measuring and justifying worst-case execution times.

• Independent laboratory skills with oscilloscopes, isolated and differential probes, current probes, electronic loads, bidirectional power supplies, and network or frequency-response analyzers.

• Familiarity with version control, code review, specifications, and test evidence.

• Experience with DS PIC is a significant plus, particularly with dsPIC33C/dsPIC33CK/dsPIC33CH, MPLAB X, and XC16.

• Preference for candidates with experience in bidirectional and multiphase interleaved converter control, average current mode control, GaN/SiC power stages, battery energy storage, EV charging, photovoltaic inverters, or grid-interactive converters.

• Familiarity with IEC 61508, ISO 26262, UL 1973, UL 1998, UL 9540, FMEA/FMEDA, MISRA C, static analysis, unit testing, HIL/PIL, SPICE/LTspice, PLECS, MATLAB/Simulink, CAN/CANopen, and embedded-bus firmware updates is preferred.

• No visa sponsorship will be provided.

🏝️ Benefits

• Equity options included in the compensation package.

• Comprehensive healthcare benefits, covering medical, dental, and vision.

• Generous paid time off and paid holidays (PTO) policy.