Why STM32G4 Is Built for Real-Time Control

The STM32G4 family consists of a 170 MHz processor - ARM Cortex M4 with hardware facilities for floating-point, DSP, mixed-signal I/O, fine-timers, and systems for mathematical calculations.

The chosen components allow 12 bit ADCs with hardware oversampling, operational amplifiers, comparators, DACs, motor control timers, high-resolution timers.

STM32G474 offers CORDIC and FMAC accelerators, five ADCs with 4 Msps speed, six op-amps, seven comparative components, and three motor control timers. These components help lower the CPU load and outside electronic components of the system.

That integration does not make every STM32G4 interchangeable. Pin count, flash and RAM, ADC allocation, HRTIM availability, temperature grade, communications, and simultaneous peripheral use determine the correct ordering code. We create a resource map before freezing the MCU or PCB.

Two Control Domains, One Engineering Discipline

Motor drives and switched-mode supplies serve different loads, but both must measure a noisy system, execute control law by a fixed deadline, update switches precisely, and reach a safe state before a fault causes damage.

Engineering domain Typical algorithms and functions Representative products
Motor control FOC, Clarke/Park transforms, PI current loops, SVPWM, observers, speed and position loops Pumps, fans, compressors, robotics, drones, tools, appliances
Digital power Voltage/current-mode control, digital compensation, phase and frequency control, soft start, current sharing Buck/boost, PFC, LLC, battery chargers, inverters, LED and industrial supplies

Relevant Case Studies Proving Our Expertise

The following published projects demonstrate relevant delivery experience. Where another MCU was used, we identify it openly and apply only the transferable engineering evidence.

STM32G4 FOC and Motor-Control Services

Motor and power-stage characterization

Control works on the principles of the motor plus inverter. We define such terms as bus range, phase current, pole pairs, resistance, inductance, flux linkage, inertia, load, speed, switching frequency, and boundaries for temperature.

The ST Motor Profiler and MCSDK make the identification of PMSM faster; however, the test data must also be analyzed at the workbench and tested at all necessary temperatures.

Sensored and sensorless FOC

We deploy d/q current loops, torque, speed or position loops, coordinate transformations, space vector pulse width modulation, current reconstruction, motor alignment, braking, and transition between state.

Sensors used for feedback might include Hall devices, encoders, resolver interfaced externally, or observer based on sensorless technology.

Sensorless control is application-specific. Startup load, low-speed observability, acceleration, field weakening, and regeneration change the design. We evaluate applicable MCSDK observer options, including STO/PLL and CORDIC-based processing, then validate the complete speed-torque envelope.

Current sensing and analog integration

We develop one-, two-, three-shunt, or isolated current-sensing architectures, including gain, calibration, ADC triggers, blanking, reconstruction, filtering, and overcurrent thresholds.

Integrated op-amps and comparators may reduce BOM and latency, external devices remain preferable where isolation, accuracy, or safety requires them.

Startup, efficiency, and acoustic refinement

When it comes to our tuning process, we adjust variables such as ramps, dead times, modulation, flux weakening, and maximum torque per amp depending on the case. We also consider feed-forward terms and loop bandwidth.

We conduct testing such as stall, reversal, load steps, bus variation, temperature, low-speed cogging, vibration, audible tones, braking energy, and starting repeatedly.

For related end-to-end capabilities, see our BLDC motor controller PCB and firmware development services.

STM32G4 Digital Power Development

Converter topology and control-loop design

We provide assistance for buck circuits, boost circuits, buck-boost circuits, flyback circuits, phase-shifted circuits, and resonant circuits, PFC levels, regulating units, LED drivers, and supply components. Coverage is determined by power, switch technology, isolation, voltage, safety, and efficiency.

Firmware can cover PWM, synchronized ADC sampling, digital compensation, current and voltage loops, feed-forward, soft start, burst modes, synchronous rectification, current sharing, pre-charge, discharge, and state sequencing. Compensation is derived, then confirmed through frequency-response or transient measurements.

High-resolution timing and fast protection

HRTIM's controller allows the STM32G4 to develop sophisticated waveforms with very tight control suitable for high-frequency conversion. The functionality of complementary output generation, dead time, phase shift, repetition frequency, burst mode, ADC trigger signaling, and fault inputs are specified here.

Break paths are enabled and disable the switching in case of a fault occurrence, without waiting for the software task.

The B-G474E-DPOW1 Discovery kit is a useful starting point, with an onboard buck-boost converter, USB Power Delivery, and power-conversion examples. A kit may prove an algorithm; custom magnetics, gate drive, isolation, creepage, thermal design, and PCB parasitics still determine product performance.

Firmware Architecture, Diagnostics, and Connectivity

In the synchronized interrupt paths, time-critical control operates independently from the type of operations performed in slower state machines, like communications, logging, and user interface.

We do a cost estimation according to the worst case execution time of each task, prioritize interrupts, place critical code and data in appropriate locations and instrument deadlines. CORDIC and FMAC are used where profiling indicates advantage.

Product firmware may include CAN FD, UART, SPI, I2C, USB, Modbus, diagnostics, calibration storage, a bootloader, updates, event history, and manufacturing mode. Telemetry cannot starve the control loop. Fault snapshots preserve key measurements and controller state around a trip.

Custom Inverter and Power-Control PCB Design

Adequate Infosoft can deliver a control board or complete electronics: schematic, gate drivers, power switches, sensing, isolation, supplies, encoder interfaces, protection, communications, multilayer PCB, BOM, prototypes, and production-test points.

Layout is part of control performance. We minimize switching loops, define gate returns, apply Kelvin sensing, separate power and measurement paths, control common-mode currents, and manage heat. High-voltage designs also require appropriate creepage, clearance, insulation, discharge behavior, and safety review. Learn more about our STM32 PCB design and prototyping services.

Protection Is a System, Not a Single Threshold

We combine hardware-fast protection with firmware supervision: cycle-by-cycle overcurrent, short circuit, gate-driver fault, shoot-through prevention, bus under/overvoltage, overtemperature, overspeed, stall, phase loss, sensor plausibility, watchdog, brownout, communications timeout, and safe restart.

A trip must produce a defined outcome. Tests verify how outputs are disabled, whether energy can regenerate into the bus, what remains latched, which evidence is stored, and what authorization or cooldown is required before restart. Safety-related products may require independent protection, formal hazard analysis, traceability, and standards-specific development beyond standard firmware testing.

Verification from Model to Loaded Hardware

Verification progresses through simulation, unit tests, processor- or hardware-in-the-loop tests, low-voltage bring-up, dynamometer or electronic-load testing, and operation across the specified envelope.

Evidence may include loop bandwidth, speed regulation, torque ripple, efficiency, startup success, position accuracy, transient response, output ripple, protection time, EMC pre-scan, thermal rise, CPU headroom, and endurance. Conditions, firmware, PCB revision, calibration, and instruments are recorded for reproducibility.

Frequently Asked Questions

Is STM32G4 suitable for sensorless FOC?

Definitely yes. STM32G4 is part of ST's motor control ecosystem supporting PMSM/BLDC FOC and the sensorless observer options.

Whether the component is appropriate for a specific application depends on factors such as the starting load, minimum speed of operation, motor characteristics, sensing, inverter design, and dynamics.

Can one STM32G4 control two motors?

Selected STM32G4 devices and MCSDK configurations support dual-motor designs, but ADC, timer, DMA, CPU, memory, and pin allocation must be proven for the required PWM and loop rates. Separate safety paths may also be necessary.

Do you modify existing STM32 motor-control firmware?

Definitely yes. ST has the capability to analyze the MCSDK-based firmware or any other firmware made by the customer, replicate the bugs discovered in the firmware, investigate the timing, optimize sensing/control, add the communication/protection features, perform the migration between the STM32 devices, and create the regression testing before the release.

Editorial Sources

Ashok Patel
Ashok Patel
Senior Engineering Project Manager
AI/ML, DevOps, Data Science & Automation | IoT & C#/.NET | Azure & AWS Expert | Certified AI & Cloud Engineer | 1,500+ LinkedIn Followers
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