Choosing the right microcontroller isn’t just about specs on paper — it’s about solving practical engineering problems under real constraints. Maybe you're stuck with an aging STM32F103 in a design that needs better power management, or you're building a new product and unsure if STM32G’s added features justify a slightly higher cost.
This guide addresses those exact trade-offs: performance vs. cost, legacy reuse vs. forward compatibility, integration vs. simplicity. Whether you're a student designing your first board or an engineer responsible for a production rollout, we’ll walk you through the practical differences and help you make the best long-term decision.
STM32F vs STM32G at a Glance
Before diving into specs, it's important to understand the philosophy and positioning behind these two series:
STM32F Series is ST’s mature, well-supported general-purpose line. It excels in cost-sensitive projects, educational use, and applications where performance demands are modest. Its wide adoption means tons of existing tools, tutorials, and board compatibility.
STM32G Series is designed as the next-generation alternative, with improvements in power efficiency, peripheral richness, analog integration, and signal-processing capabilities. It targets new designs needing lower power, tighter analog precision, or real-time responsiveness.
The STM32F and STM32G series differ in three major dimensions: core performance, power efficiency, and peripheral integration. STM32G is built as a newer generation, targeting applications that demand low power, analog precision, and faster compute.
| Feature | STM32F103 (Typical) | STM32G431 (Typical) |
|---|---|---|
| Core | Cortex-M3 @ 72 MHz | Cortex-M4 @ 170 MHz + FPU |
| Flash/RAM | Up to 1MB / 96KB | Up to 512KB / 128KB |
| ADC | 12-bit, 1 MSPS | 12-bit, up to 4 MSPS |
| Math Acceleration | None | FPU, CORDIC, FMAC |
| Low-Power Mode | Basic sleep/stop | Multiple modes, STOP ~1.3 µA |
| Analog Integration | Basic ADC/DAC | Op-amps, comparators, gain amplifier |
| PWM Resolution | Standard (16-bit timers) | HRPWM (high-resolution) |
These differences make STM32G suitable for more advanced and compact designs, while STM32F remains a cost-effective choice for general-purpose applications and legacy projects.
For detailed technical specs, see the STM32 Product Selector.
Key Evaluation Criteria for MCU Selection
Power Consumption Requirements
If your design needs to run on a coin cell or enter long sleep cycles (think IoT sensors, wearable devices), STM32G0 or G4 offer significant power savings. STM32F1 and F4 lack comparable low-power modes.
STM32G071CB can run with as low as 1.7V and enter STOP mode with ~1.3 µA current — ideal for battery-powered remote sensors.
Processing and Signal Handling
STM32G4 offers hardware math support: FPU, CORDIC, and high-speed ADCs — ideal for real-time motor control, digital filters, or audio processing. STM32F103 lacks these, making it less suitable for compute-heavy applications.
STM32G431KB includes 12-bit 4MSPS ADCs, op-amps, and a motor control timer, making it highly suitable for BLDC motor drivers.
Refer to STM32G4 Overview for examples of these capabilities in industrial and precision applications.
Hardware and Software Legacy
If you're updating an existing design based on STM32F103 or F407, staying within the F series may reduce risk. STM32CubeIDE and HAL libraries support both, but hardware differences (e.g., voltage domains, I/O mapping) can affect migration.
STM32F407VET6 is still widely used in data logging and industrial control, thanks to its mature ecosystem, Ethernet support, and high-speed I/Os.
ST's F1 to G4 migration guide provides a comprehensive compatibility checklist.
Summary Matrix: Which MCU Series Suits Your Project?
To simplify decision-making, here's a concise summary of when to choose STM32F vs STM32G:
| Situation | Recommended Series | Why |
|---|---|---|
| Tight cost constraints, basic control logic | STM32F103 | Low price, widely supported, good for simple applications |
| Need low power for battery or standby | STM32G071 | Optimized for ultra-low-power with STOP modes < 2 µA |
| Require math-intensive processing (e.g. FPU, FFT) | STM32G431 / G474 | Comes with FPU, CORDIC, FMAC — ideal for DSP and control loops |
| Migrating from legacy F1/F4 hardware | STM32F103 / F407 | Minimizes redesign work and preserves existing firmware |
| Analog integration (op-amps, comparators) needed | STM32G4 series | Reduces external components and boosts precision |
| Starting a new industrial or high-performance design | STM32G4 series | High-speed ADC, HRPWM, low latency for control applications |
In short: choose STM32F for cost-sensitive or legacy continuity. Choose STM32G when performance, power efficiency, or analog precision are required in new designs.
Application Scenarios and Recommendations
| Scenario | Recommended MCU | Reasoning |
|---|---|---|
| Educational kits or hobby projects | STM32F103C8T6 | Inexpensive, widely available, strong community support |
| Industrial motor control | STM32G431KB | HRPWM, op-amps, FPU, and comparators integrated; ideal for PMSM/BLDC drivers |
| Battery-powered IoT sensors | STM32G071CB | STOP mode < 2 µA, 1.7V operation, QFN package for compact design |
| DSP / audio / signal processing | STM32G474RE | FPU, CORDIC, FMAC (Filter Math Accelerator), 4MSPS ADCs for fast sampling |
| Home appliances (AC control, compressors) | STM32G431C6 | Motor control library support, temperature-tolerant features |
| Portable medical devices (e.g., glucometers) | STM32G070RB | Low-power design with accurate ADC and reduced analog component count |
| Multi-protocol communication gateway | STM32F407VET6 | Integrated Ethernet, multiple UART/SPI/I2C, proven long-term support |
| Power monitoring / metering | STM32G474QET6 | 16-bit ADC with programmable gain, phase-shift PWM for power stages |
| USB-C PD and charging controllers | STM32G0B1RE | Type-C/PD stack support, dead-time insertion, low power consumption |
This expanded list covers both high-performance and cost-sensitive designs across industrial, consumer, medical, and smart device applications.
Migration Considerations
Moving from F to G isn't a copy-paste process. While ST’s CubeIDE offers cross-series compatibility, be prepared to:
- Reconfigure clock trees and power supply
- Adjust to new peripheral naming and capabilities
- Validate analog precision changes
Start with dev boards like Nucleo-G431 and leverage ST’s official migration notes for smooth transitions.
Conclusion
The STM32F series remains a solid choice for legacy systems, tight budgets, and simple designs. But if you're building something new — and especially if you need performance, efficiency, or integration — the STM32G series is where ST is heading.
Choosing the right chip isn’t just about specs — it’s about aligning technology with your product’s long-term needs.
