STM32F303CBT6

The STM32F303CBT6 from STMicroelectronics is a mainstream mixed-signal microcontroller from the STM32F3 series, based on the ARM Cortex-M4 core with floating-point unit (FPU) and DSP instructions operating at up to 72MHz. What distinguishes the STM32F303 from other STM32 families is its exceptional analog peripheral integration: four independent 12-bit ADCs capable of 5MSPS each (enabling simultaneous sampling of multiple signals), seven fast rail-to-rail comparators, four operational amplifiers with programmable gain (PGA mode), and two 12-bit DAC channels. This rich analog subsystem makes the STM32F303 ideal for mixed-signal applications that require both digital processing and precision analog interfacing in a single chip. The four ADCs can be triggered simultaneously from different timer sources, enabling precise multi-channel measurement for motor control (three-phase current sensing) and power conversion applications. The seven comparators provide fast overcurrent and overvoltage protection with minimal latency, critical for motor drive and power converter safety. The four internal op-amps eliminate external amplifier circuits for signal conditioning, with all terminals accessible for flexible configuration as inverting/non-inverting amplifiers, followers, or PGA with programmable gains of 2, 4, 8, 16, 32, or 64. The two advanced motor control timers with PWM generation, dead-time insertion, and emergency stop support Field Oriented Control (FOC) of brushless DC motors and PMSM motors.

The STM32F303CBT6 operates as a mixed-signal Cortex-M4 microcontroller. Key subsystems include: (1) Cortex-M4F Core – a 32-bit RISC processor with single-cycle DSP instructions (MAC, SIMD) and single-precision FPU; the FPU accelerates floating-point motor control algorithms (Park/Clarke transforms, PID); 90 DMIPS performance from the CCM RAM; (2) Four ADCs – four independent 12-bit successive-approximation ADCs, each with 5MSPS conversion rate and up to 10 external channels; the ADCs can operate in dual or triple interleaved mode for higher effective sampling rates; each ADC has its own trigger source from different timers, enabling simultaneous multi-channel sampling; the 12/10/8/6-bit resolution is configurable for speed vs. accuracy tradeoff; (3) Op-Amps – four internal rail-to-rail operational amplifiers with all terminals (inverting input, non-inverting input, output) accessible on external pins; each op-amp can be configured as a voltage follower, inverting amplifier, or PGA with programmable gain; the PGA mode amplifies small sensor signals (e.g., current shunt voltage) before ADC conversion, improving signal-to-noise ratio; (4) Comparators – seven rail-to-rail comparators with programmable hysteresis and speed/power tradeoff; the fast mode provides 30ns propagation delay for overcurrent protection; the output can be connected to timer break inputs for immediate PWM shutdown; (5) Motor Control Timers – two advanced 16-bit timers (TIM1 and TIM20) with up to 6 PWM channels, complementary outputs with programmable dead-time, and break input for emergency shutdown; the break input from comparators provides hardware-level overcurrent protection with minimal latency.

• BLDC motor FOC: 3 ADCs simultaneously sample phase currents, op-amps amplify shunt voltage, comp for overcurrent, timer PWM with dead-time
• Power inverter: 4 ADCs sample voltage and current, DAC generates reference, comp for fault protection, CAN for communication
• Medical ECG: op-amps amplify bio-potential, 12-bit ADC digitizes, DSP filters, USB transmits data to PC
• Industrial sensor: 4 ADCs read multiple sensor channels simultaneously, PGA amplifies low-level signals, touch sense for user interface