Senior Power Electronics Firmware Engineer

Tonal • San Francisco, CA

2d

About The Position

Tonal is seeking a Senior Power Electronics Firmware Engineer to develop firmware for its motor drive and power systems. The drive generates up to 250 pounds of digital weight, and its firmware shapes the experience for members. The engineer will contribute throughout development, from concept, prototyping, and bring-up through validation and high-volume production.

The role is part of the Firmware team in the Hardware department and involves close collaboration with electrical, mechanical, and software engineers. The team works on challenges spanning motor control, power conversion, thermal limits, and member safety.

Requirements

• At least 5 years of embedded firmware development experience, including at least 3 years focused on motor control or power electronics.
• Expertise in C development for real-time, resource-constrained systems.
• Experience developing multithreaded firmware on an RTOS, including scheduling, synchronization, and interrupt handling for timing-critical tasks.
• Hands-on experience implementing field-oriented control (FOC) for PMSM/BLDC motors, including current-loop tuning and sensored or sensorless position estimation.
• Solid power electronics fundamentals, including inverters, DC-DC converters, PWM techniques such as SVPWM, gate drivers, current and voltage sensing, and thermal behavior.
• Experience designing discrete-time control loops, filters, and observers, and modeling them in MATLAB/Simulink or Python.
• Experience with motor-control MCUs or DSPs such as TI C2000, STM32, or NXP, and communication protocols such as CAN, UART, SPI, and I2C.
• Experience with safety-critical systems, including protection, fault handling, and diagnostics for high-power hardware.
• Comfort debugging at the hardware/firmware boundary using oscilloscopes, current and differential probes, power analyzers, and dynamometers.
• Creative problem-solving, willingness to push boundaries and think differently, and strong attention to detail.
• Strong oral and written communication skills.
• Team-oriented approach, high integrity and self-awareness, openness to feedback, and a commitment to continuous improvement.

Nice To Haves

• Experience with functional or appliance safety standards such as IEC 60730 (Class B software), IEC 60335, IEC 61508, or ISO 26262.
• Experience managing regenerative energy in motor drives, such as braking resistor control and DC bus regulation.
• Experience with digitally controlled power conversion, such as PFC or DC-DC stages.
• Experience with unit testing, software- and hardware-in-the-loop (SIL/HIL) testing, Git, and CI tools such as Jenkins.
• Experience with EMC/EMI and safety compliance testing for motor drives.
• Experience with bootloaders and secure over-the-air firmware updates.
• Experience shipping high-volume consumer hardware.
• Experience in C++ and Python.

Responsibilities

• Develop and improve motor control and power management firmware to make Tonal’s digital weight feel smooth and responsive.
• Add and maintain protection features, including overcurrent and overtemperature handling, to help keep members safe.
• Bring up and debug new boards in the lab with the electrical team.
• Test and tune motor performance, and help build tools and automated tests to validate releases.
• Support manufacturing test and calibration, and help investigate field issues.
• Work with software, mechanical, and product teams to turn member feedback into firmware improvements.
• Participate in design and code reviews and help improve how the team builds and ships firmware.

What This Job Offers

• Job Type: Full-time
• Career Level: Senior
• Education Level: No Education Listed