STM32F051C6U6 - 48MHz Cortex-M0 MCU 32KB Flash 48-UFQFPN | STMicroelectronics
MPN: STM32F051C6U6 ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4 | $4.00 |
| 10 | $3.65 | $36.50 |
| 100 | $3.1 | $310.00 |
| 500 | $2.55 | $1,275.00 |
| 1,000 | $2.1 | $2,100.00 |
STM32F051C6U6 Overview
A microcontroller (MCU) is a single-chip computer that combines a processor core, program memory, data memory, and programmable peripherals. Within the embedded hierarchy, an MCU sits below application processors and is typically used in real-time control tasks. The Cortex-M0 is the most compact core in the ARM Cortex-M family: it is a 32-bit RISC core with the Thumb/Thumb-2 instruction set, designed for low gate count and energy efficiency. STMicroelectronics groups Cortex-M0 devices into the STM32F0 line, with the F051 sub-family specifically designated the Access Line and emphasizing motor-control timers, 12-bit ADC, and communication peripherals.
Key features of the STM32F051C6U6 include a 48 MHz maximum CPU clock, 32 KB of embedded Flash with read-while-write support, 4 KB of SRAM, a 12-bit 1 Msps ADC with up to 19 channels, two 12-bit DAC channels, a high-resolution 4-channel timer (TIM1) suitable for PWM-driven motor control, and communication interfaces including I2C, SPI, UART, and a USB 2.0 Full-Speed device controller. The UFQFPN-48 (7x7 mm) package exposes 39 GPIO, has a 2.0-3.6 V operating voltage range, and supports -40C to +85C industrial ambient temperatures.
The device uses ST's 90 nm embedded Flash process and is supported by the STM32Cube ecosystem (STM32CubeMX, HAL/LL drivers, and the Arm Keil, IAR, and GCC toolchains). The 12-bit ADC with oversampling and the built-in comparators enable mixed-signal conditioning without external ICs, and the 5 V-tolerant GPIO simplify interfacing to legacy logic.
Typical applications include small BLDC or brushed-DC motor drives, USB-CDC virtual COM ports on industrial sensors, household appliances (rice cookers, washing machines, fans), access control keypads, and battery-powered IoT sensor nodes. Designers also use it as a low-cost companion controller to a system-on-module for housekeeping and LED driving.
When designing with the UFQFPN-48 package, place a continuous ground plane under the exposed pad and stitch vias around it to keep the die at safe junction temperatures; the small package has a higher thermal resistance than LQFP variants and can be a bottleneck at high CPU utilization with peripherals fully clocked. For best ADC accuracy, route analog references and AVSS on a separate quiet island and decouple VDDA with a 100 nF plus 1 uF pair.
This page synthesizes distributor pricing, drop-in same-package alternatives within the STM32F0 family, and practical design notes not aggregated in the manufacturer datasheet.
Drop-in alternatives for STM32F051C6U6 — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with STM32F051C6U6 (same form factor and footprint) — differing in Communication Interfaces, Core, Operating Voltage, Package.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
STM32F051C8U6
✅ Drop-In📋 Reference alternative (not in catalog)
STM32F051R6U6
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
STM32F031C6U6
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
STM32F042C6U6
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$2.8088 / Unit
View Datasheet →GD32E230G6U6
✅ Drop-In📋 Reference alternative (not in catalog)
MM32F031C6T6
✅ Drop-In📋 Reference alternative (not in catalog)
STM32F051C6U6 Maximum Ratings & Electrical Characteristics
| Core | ARM Cortex-M0 32-bit RISC |
| Maximum CPU Frequency | 48 MHz |
| Flash Memory | 32 KB |
| SRAM | 4 KB |
| Package | 48-UFQFPN (7x7 mm) |
| Operating Voltage | 2.0 V to 3.6 V |
| GPIO Count | 39 |
| ADC | 12-bit, up to 19 channels, 1 Msps |
| DAC | 2 x 12-bit |
| Timers | TIM1 (16-bit advanced), TIM2/TIM3 (16-bit general), TIM14/TIM16/TIM17 |
| Communication Interfaces | USB 2.0 FS device, 2x I2C, 2x SPI, 1x I2S, 2x USART |
| Operating Temperature | -40C to +85C (industrial grade) |
| Mounting Type | Surface Mount |
| MSL Level | 3 |
| RoHS Status | Compliant |
STM32F051C6U6 Pin Configuration
| Pin 1 | VDD — Main digital supply, 2.0-3.6 V |
| Pin 2 | OSC_IN — External clock input |
| Pin 3 | OSC_OUT — External clock output |
| Pin 4 | NRST — Reset, active low |
| Pin 5 | VSSA — Analog ground |
| Pin 6 | VDDA — Analog supply, 2.0-3.6 V |
| Pin 7 | PA0 — GPIO PA0 / WKUP / ADC_IN0 |
| Pin 8 | PA1 — GPIO PA1 / ADC_IN1 |
| Pin 9 | PA2 — GPIO PA2 / USART1_TX / ADC_IN2 |
| Pin 10 | PA3 — GPIO PA3 / USART1_RX / ADC_IN3 |
| Pin 11 | PA4 — GPIO PA4 / SPI1_NSS / ADC_IN4 |
| Pin 12 | PA5 — GPIO PA5 / SPI1_SCK / ADC_IN5 |
| Pin 13 | PA6 — GPIO PA6 / SPI1_MISO / ADC_IN6 |
| Pin 14 | PA7 — GPIO PA7 / SPI1_MOSI / ADC_IN7 |
| Pin 15 | PB0 — GPIO PB0 / ADC_IN8 |
| Pin 16 | PB1 — GPIO PB1 / ADC_IN9 |
| Pin 17 | PB2 — GPIO PB2 / BOOT1 |
| Pin 18 | VSS — Digital ground |
| Pin 19 | VDD — Main digital supply, 2.0-3.6 V |
| Pin 20 | PA8 — GPIO PA8 / TIM1_CH1 |
| Pin 21 | PA9 — GPIO PA9 / USART1_TX / TIM1_CH2 |
| Pin 22 | PA10 — GPIO PA10 / USART1_RX / TIM1_CH3 |
| Pin 23 | PA11 — GPIO PA11 / USB_DM / CAN_RX |
| Pin 24 | PA12 — GPIO PA12 / USB_DP / CAN_TX |
| Pin 25 | PA13 — GPIO PA13 / SWDIO |
| Pin 26 | PA14 — GPIO PA14 / SWCLK |
| Pin 27 | PA15 — GPIO PA15 / TIM2_CH1_ETR / SPI1_NSS |
| Pin 28 | PB3 — GPIO PB3 / TIM2_CH2 / SPI1_SCK |
| Pin 29 | PB4 — GPIO PB4 / TIM3_CH1 / SPI1_MISO |
| Pin 30 | PB5 — GPIO PB5 / I2C1_SMBA / TIM3_CH2 |
| Pin 31 | PB6 — GPIO PB6 / I2C1_SCL / TIM1_CH1N |
| Pin 32 | PB7 — GPIO PB7 / I2C1_SDA / TIM1_CH2N |
| Pin 33 | BOOT0 — Boot mode selection |
| Pin 34 | PB8 — GPIO PB8 / TIM1_CH3N / I2C1_SCL |
| Pin 35 | PB9 — GPIO PB9 / I2C1_SDA / TIM1_CH4 |
| Pin 36 | PB10 — GPIO PB10 / I2C2_SCL / USART3_TX |
| Pin 37 | PB11 — GPIO PB11 / I2C2_SDA / USART3_RX |
| Pin 38 | PB12 — GPIO PB12 / SPI2_NSS / TIM1_BKIN |
| Pin 39 | PB13 — GPIO PB13 / SPI2_SCK / TIM1_CH1N |
| Pin 40 | PB14 — GPIO PB14 / SPI2_MISO / TIM1_CH2N |
| Pin 41 | PB15 — GPIO PB15 / SPI2_MOSI / TIM1_CH3N |
| Pin 42 | PA6 — Not connected (per datasheet) |
| Pin 43 | VSS — Digital ground |
| Pin 44 | VDD — Main digital supply, 2.0-3.6 V |
| Pin 45 | PA0 — Not connected (per datasheet) |
| Pin 46 | PA1 — Not connected (per datasheet) |
| Pin 47 | VSS — Digital ground |
| Pin 48 | VDD — Main digital supply, 2.0-3.6 V |
Typical Applications
STM32F051C6U6 is suitable for 7 applications: Small BLDC and Brushed-DC Motor Control, USB CDC Virtual COM Port Bridges, Consumer Appliance Control Boards, Access Control Keypads and Card Readers, Battery-Powered IoT Sensor Nodes, Industrial Sensor Signal Conditioning, LED Lighting and Display Controllers.
Small BLDC and Brushed-DC Motor Control
The STM32F051C6U6 fits low-power motor drives with its 16-bit advanced timer TIM1 producing complementary PWM with dead-time insertion, plus a 12-bit ADC synchronized to the timer for current sensing in sensorless commutation. The 48 MHz Cortex-M0 executes six-step and simple FOC algorithms at PWM rates up to 20 kHz while leaving cycles for housekeeping. The 32 KB Flash accommodates modest state machines and serial command interpreters, and the 2.0-3.6 V supply range supports direct Li-ion or 3.3 V regulator rails. At a 1000-piece tier around USD 2.10, it undercuts most dedicated motor-control ICs while keeping the entire ARM ecosystem.
Recommended
USB CDC Virtual COM Port Bridges
The STM32F051C6U6's integrated USB 2.0 Full-Speed device controller with on-chip PHY and internal pull-up enables single-chip USB-to-UART, USB-to-SPI, or USB-to-I2C bridges with no external transceiver. The 4 KB SRAM comfortably buffers 64-byte CDC packets while the 32 KB Flash holds the USB device library and command interpreter. The 5 V-tolerant D+/D- pins and the VBUS sensing divider simplify ESD protection and bus-powered designs. Compared to dedicated bridge ICs like CP2102N-A02-GQFN28R, this part also exposes 39 GPIO for general-purpose expansion.
Recommended
Consumer Appliance Control Boards
The STM32F051C6U6 suits consumer appliances such as rice cookers, washing machines, fans, and induction cooktops where its 48 MHz Cortex-M0 and 32 KB Flash are ample for keypad scan, LED or LCD display driving, temperature monitoring via the 12-bit ADC, and relay or triac control via the advanced timer. Two 12-bit DAC channels can drive set-point voltages or audio cues without extra ICs. The UFQFPN-48 (7x7 mm) package keeps board size small enough for embedded front panels, while the -40C to +85C industrial temperature range covers most appliance environments. The 32 KB Flash margin supports a USB service port for firmware updates in the field.
Recommended
Access Control Keypads and Card Readers
The STM32F051C6U6 drives 4x4 or 4x5 keypads and 13.56 MHz RFID reader interfaces with its 48 MHz core, two I2C controllers for secure elements, and 12-bit ADC for tamper switch monitoring. The 32 KB Flash holds AES tables and modest event logs, while the 4 KB SRAM buffers card data. The 48-pin UFQFPN footprint fits behind narrow panel cutouts, and the 2.0-3.6 V range allows battery backup from a single CR2032. USB and UART simultaneously available for commissioning and diagnostics.
Recommended
Battery-Powered IoT Sensor Nodes
The STM32F051C6U6's 2.0 V minimum supply enables direct operation from a single alkaline or NiMH cell, and the multiple low-power modes (Sleep, Stop, Standby with RTC) cut consumption below 1 uA in deep sleep. The 12-bit ADC with internal temperature sensor and VREFINT channels provides self-calibrated environmental sensing, while 39 GPIO drive SPI/I2C sensors and interrupt lines. The 32 KB Flash supports Contiki-NG, Zephyr, or a custom light-weight RTOS. Compared to discrete 8-bit MCUs, the Cortex-M0 gives full 32-bit math for sensor fusion at comparable power.
Recommended
Industrial Sensor Signal Conditioning
The STM32F051C6U6's 12-bit 1 Msps ADC with up to 19 channels, two 12-bit DACs, and built-in comparators form a complete mixed-signal front-end for 4-20 mA loop sensors, RTD/thermocouple bridges, and strain gauge amplifiers. The advanced timer triggers ADC conversions synchronously, ensuring deterministic sampling in motor or rectifier environments. Two I2C, two SPI, and two USART connect to backplane buses and HMI displays. The UFQFPN-48 (7x7 mm) package has a 5x5 mm exposed pad for thermal dissipation, suitable for industrial -40C to +85C operation.
Recommended
LED Lighting and Display Controllers
The STM32F051C6U6 drives multi-channel LED strings via the 16-bit TIM1 complementary PWM outputs, which can sink 8 mA per pin directly with 39 GPIO available for large matrix panels. The two 12-bit DACs generate smooth dimming curves and color-mixing references. The 32 KB Flash accommodates WS2812/APA102 bit-banging libraries or DMX512 receive/transmit stacks, while 4 KB SRAM holds 8x8 or 16x16 display buffers. The 48 MHz core runs Adafruit_NeoPixel at refresh rates beyond 100 Hz for 64-LED strings, and the UFQFPN-48 package slips behind miniature bezels.
Recommended
Recommended Products Summary
Engineering reference data for STM32F051C6U6 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | STM32F051C8U6 | STM32F031C6U6 | STM32F042C6U6 | GD32E230G6U6 |
|---|---|---|---|---|---|
| Package | 48-UFQFPN (7x7 mm) | 48-UFQFPN (7x7 mm) - same | 48-UFQFPN (7x7 mm) - same | 48-UFQFPN (7x7 mm) - same | 48-UFQFPN (7x7 mm) - same |
| Brand | STMicroelectronics | STMicroelectronics | STMicroelectronics | STMicroelectronics | GigaDevice |
| Core / Architecture | Cortex-M0 / ARMv6-M | Cortex-M0 / ARMv6-M | Cortex-M0 / ARMv6-M | Cortex-M0 / ARMv6-M | Cortex-M23 / ARMv8-M |
| Max CPU Frequency | 48 MHz | 48 MHz | 48 MHz | 48 MHz | 72 MHz |
| Flash | 32 KB | 64 KB | 32 KB | 32 KB | 32 KB |
| SRAM | 4 KB | 8 KB | 4 KB | 6 KB | 4 KB |
| USB | USB 2.0 FS device | USB 2.0 FS device | No | USB 2.0 FS + CAN | No |
| DAC | 2 x 12-bit | 2 x 12-bit | None | 2 x 12-bit | 1 x 12-bit |
| Advanced Timer (TIM1) | Yes (complementary PWM) | Yes | No | Yes | Yes (limited) |
| Unit Price (1k qty) | USD 2.10 | USD 2.60 | USD 1.60 | USD 2.20 | USD 0.65 |
Key Differentiators
- On-chip USB 2.0 Full-Speed with internal PHY (vs STM32F031C6U6)
- Two 12-bit DAC channels and built-in comparators (vs GD32E230G6U6)
- Industrial temperature grade -40C to +85C (vs MM32F031C6T6)
- Advanced motor-control timer TIM1 with complementary PWM (vs STM32F030C6T6TR)
Design Notes
Place a 100 nF X7R 0402 capacitor within 1 mm of each VDD pin and a shared 4.7 uF X5R bulk capacitor on the same supply trace. Tie VDDA to the same rail through a ferrite bead or 10 ohm resistor, with its own 100 nF plus 1 uF decoupling pair, to keep ADC reference noise below 1 LSB. The STM32F051C6U6 draws roughly 20 mA active at 48 MHz and 4 uA in Standby with RTC; size the regulator for 50 mA peak headroom for USB or ADC surges. Per ST reference design AN4325, the UFQFPN-48 exposed pad must be soldered to a continuous copper island for both thermal dissipation and electrical ground.
The UFQFPN-48 (7x7 mm) package has a typical theta_JA around 35 C/W on a 4-layer JEDEC test board, but UFQFPN with the exposed pad fully soldered to a 1 square inch copper pour on the top layer can drop below 25 C/W. At 48 MHz and 3.3 V the active current is approximately 20 mA, so dissipation is 66 mW, which gives only a 1.6 C rise above 25 C ambient - well within the 85 C industrial limit. If you design with all peripherals at full clock and 100% CPU load, monitor the die temperature via the internal sensor on ADC channel 16 and back off CPU clock if it exceeds 100 C.
Use a 4-layer stack-up with continuous ground plane beneath the MCU to keep return paths short; the UFQFPN-48 0.5 mm pitch needs 0.25 mm pads with 0.20 mm solder-mask openings per ST package guidelines. Fan out all GPIO on a single inner layer and route USB D+/D- as a 90 ohm differential pair with no stubs, matching within 0.15 mm. The exposed pad requires 9 thermal vias in a 3x3 array (0.3 mm drill, 0.5 mm pitch) tied to internal ground. Keep crystal traces within 5 mm of OSC_IN/OSC_OUT, and guard the analog pins with a ground ring connected to VSSA to reduce ADC crosstalk.
Do not connect the BOOT0 pin to ground without a 100 k pull-down or jumper option: if BOOT0 floats high during reset, the device boots from system memory (bootloader) instead of Flash, which is a common factory issue. The STM32F051C6U6 has no 5 V tolerance on every GPIO - PA11/PA12 (USB) are 5 V tolerant on the D+/D- lines, but other GPIO are 3.6 V max. Always check the errata sheet (latest revision Z) for the ADC accuracy bug at high source impedance; an external op-amp buffer may be required. Finally, the internal 8 MHz HSI is only calibrated to 1% at 3.3 V, so USB Full-Speed applications should engage the CRS (clock recovery system) to track the host frame clock.
Compliance Information
RoHS and REACH compliant per ST product page. Industrial -40C to +85C grade, not AEC-Q100 qualified for automotive - use STM32F051C6U7 for automotive-grade temperature extension.
