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Contents

README

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STM32L431CCU6

STMicroelectronics · Microcontrollers (MCU/MPU/SOC) · UFQFPN-48(7x7)

STM32L431CCU6 from STMicroelectronics, in a UFQFPN-48(7x7). Pinout and pin descriptions extracted from the manufacturer datasheet (extract_pins, cross-checked by a second model, then checked against ST open pin data); symbol, footprint, and 3D from KiCad-official CAD.

Pinout

Pin Name Type Function
1 VBAT power_in Backup domain supply for RTC and backup registers, 1.55 V to 3.6 V operating range.
2 PC13 bidirectional 5 V tolerant I/O supplied through the power switch (limited to 3 mA, max 2 MHz with 30 pF load in output mode); also RTC_TAMP1, RTC_TS, RTC_OUT, WKUP2.
3 PC14-OSC32_IN bidirectional 5 V tolerant I/O on the backup power switch (output mode limited to 2 MHz, 30 pF); LSE crystal input OSC32_IN.
4 PC15-OSC32_OUT bidirectional 5 V tolerant I/O on the backup power switch (output mode limited to 2 MHz, 30 pF); LSE crystal output OSC32_OUT.
5 PH0-OSC_IN bidirectional 5 V tolerant I/O, also the HSE oscillator input OSC_IN.
6 PH1-OSC_OUT bidirectional 5 V tolerant I/O, also the HSE oscillator output OSC_OUT.
7 NRST bidirectional Bidirectional reset pin with embedded weak pull-up resistor.
8 VSSA/VREF- power_in Analog ground, internally connected to the negative ADC reference VREF- in this package.
9 VDDA/VREF+ power_in Analog supply (1.62 V to 3.6 V for ADC/COMP use), internally connected to the positive reference VREF+ in this package.
10 PA0 bidirectional 5 V tolerant I/O with analog switch; TIM2_CH1, USART2_CTS, COMP1_OUT, OPAMP1_VINP, COMP1_INM, ADC1_IN5, RTC_TAMP2, WKUP1.
11 PA1 bidirectional 5 V tolerant I/O with analog switch; TIM2_CH2, I2C1_SMBA, SPI1_SCK, USART2_RTS_DE, OPAMP1_VINM, COMP1_INP, ADC1_IN6.
12 PA2 bidirectional 5 V tolerant I/O with analog switch; TIM2_CH3, USART2_TX, LPUART1_TX, QUADSPI_BK1_NCS, COMP2_INM, ADC1_IN7, WKUP4, LSCO.
13 PA3 bidirectional 3.6 V tolerant I/O with analog switch; TIM2_CH4, USART2_RX, LPUART1_RX, QUADSPI_CLK, OPAMP1_VOUT, COMP2_INP, ADC1_IN8.
14 PA4 bidirectional 3.6 V tolerant I/O with analog switch; SPI1_NSS, SPI3_NSS, USART2_CK, COMP1_INM, COMP2_INM, ADC1_IN9, DAC1_OUT1.
15 PA5 bidirectional 3.6 V tolerant I/O with analog switch; TIM2_CH1, TIM2_ETR, SPI1_SCK, COMP1_INM, COMP2_INM, ADC1_IN10, DAC1_OUT2.
16 PA6 bidirectional 5 V tolerant I/O with analog switch; TIM1_BKIN, SPI1_MISO, COMP1_OUT, USART3_CTS, QUADSPI_BK1_IO3, ADC1_IN11.
17 PA7 bidirectional 5 V tolerant Fm+ I/O with analog switch; TIM1_CH1N, I2C3_SCL, SPI1_MOSI, QUADSPI_BK1_IO2, ADC1_IN12.
18 PB0 bidirectional 5 V tolerant I/O with analog switch; TIM1_CH2N, SPI1_NSS, USART3_CK, QUADSPI_BK1_IO1, ADC1_IN15.
19 PB1 bidirectional 5 V tolerant I/O with analog switch; TIM1_CH3N, USART3_RTS_DE, LPUART1_RTS_DE, QUADSPI_BK1_IO0, COMP1_INM, ADC1_IN16.
20 PB2 bidirectional 5 V tolerant I/O with analog switch; RTC_OUT, LPTIM1_OUT, I2C3_SMBA, COMP1_INP.
21 PB10 bidirectional 5 V tolerant Fm+ I/O; TIM2_CH3, I2C2_SCL, SPI2_SCK, USART3_TX, LPUART1_RX, TSC_SYNC, QUADSPI_CLK, SAI1_SCK_A.
22 PB11 bidirectional 5 V tolerant Fm+ I/O; TIM2_CH4, I2C2_SDA, USART3_RX, LPUART1_TX, QUADSPI_BK1_NCS, COMP2_OUT.
23 VSS power_in Ground supply pin.
24 VDD power_in Main digital supply, 1.71 V to 3.6 V.
25 PB12 bidirectional 5 V tolerant I/O; TIM1_BKIN, I2C2_SMBA, SPI2_NSS, USART3_CK, LPUART1_RTS_DE, TSC_G1_IO1, SWPMI1_IO, SAI1_FS_A.
26 PB13 bidirectional 5 V tolerant Fm+ I/O; TIM1_CH1N, I2C2_SCL, SPI2_SCK, USART3_CTS, LPUART1_CTS, TSC_G1_IO2, SWPMI1_TX, SAI1_SCK_A.
27 PB14 bidirectional 5 V tolerant Fm+ I/O; TIM1_CH2N, I2C2_SDA, SPI2_MISO, USART3_RTS_DE, TSC_G1_IO3, SWPMI1_RX, SAI1_MCLK_A.
28 PB15 bidirectional 5 V tolerant I/O; RTC_REFIN, TIM1_CH3N, SPI2_MOSI, TSC_G1_IO4, SWPMI1_SUSPEND, SAI1_SD_A.
29 PA8 bidirectional 5 V tolerant I/O; MCO, TIM1_CH1, USART1_CK, SWPMI1_IO, SAI1_SCK_A, LPTIM2_OUT.
30 PA9 bidirectional 5 V tolerant Fm+ I/O; TIM1_CH2, I2C1_SCL, USART1_TX, SAI1_FS_A, TIM15_BKIN.
31 PA10 bidirectional 5 V tolerant Fm+ I/O; TIM1_CH3, I2C1_SDA, USART1_RX, SAI1_SD_A.
32 PA11 bidirectional 5 V tolerant I/O; TIM1_CH4, TIM1_BKIN2, SPI1_MISO, COMP1_OUT, USART1_CTS, CAN1_RX.
33 PA12 bidirectional 5 V tolerant I/O; TIM1_ETR, SPI1_MOSI, USART1_RTS_DE, CAN1_TX.
34 PA13 (JTMS-SWDIO) bidirectional 5 V tolerant I/O configured as JTMS-SWDIO after reset with internal pull-up active; also IR_OUT, SWPMI1_TX, SAI1_SD_B.
35 VSS power_in Ground supply pin.
36 VDD power_in Main digital supply, 1.71 V to 3.6 V.
37 PA14 (JTCK-SWCLK) bidirectional 5 V tolerant I/O configured as JTCK-SWCLK after reset with internal pull-down active; also LPTIM1_OUT, I2C1_SMBA, SWPMI1_RX, SAI1_FS_B.
38 PA15 (JTDI) bidirectional 5 V tolerant I/O configured as JTDI after reset with internal pull-up active; also TIM2_CH1, USART2_RX, SPI1_NSS, SPI3_NSS, TSC_G3_IO1.
39 PB3 (JTDO-TRACESWO) bidirectional 5 V tolerant I/O with analog switch, JTDO-TRACESWO after reset; TIM2_CH2, SPI1_SCK, SPI3_SCK, USART1_RTS_DE, SAI1_SCK_B, COMP2_INM.
40 PB4 (NJTRST) bidirectional 5 V tolerant Fm+ I/O with analog switch, NJTRST after reset with internal pull-up active; I2C3_SDA, SPI1_MISO, SPI3_MISO, USART1_CTS, COMP2_INP.
41 PB5 bidirectional 5 V tolerant I/O; LPTIM1_IN1, I2C1_SMBA, SPI1_MOSI, SPI3_MOSI, USART1_CK, COMP2_OUT, SAI1_SD_B, TIM16_BKIN.
42 PB6 bidirectional 5 V tolerant Fm+ I/O with analog switch; LPTIM1_ETR, I2C1_SCL, USART1_TX, SAI1_FS_B, TIM16_CH1N, COMP2_INP.
43 PB7 bidirectional 5 V tolerant Fm+ I/O with analog switch; LPTIM1_IN2, I2C1_SDA, USART1_RX, COMP2_INM, PVD_IN.
44 PH3/BOOT0 bidirectional 5 V tolerant I/O (PH3) that also serves as the BOOT0 boot-mode pin.
45 PB8 bidirectional 5 V tolerant Fm+ I/O; I2C1_SCL, CAN1_RX, SDMMC1_D4, SAI1_MCLK_A, TIM16_CH1.
46 PB9 bidirectional 5 V tolerant Fm+ I/O; IR_OUT, I2C1_SDA, SPI2_NSS, CAN1_TX, SDMMC1_D5, SAI1_FS_A.
47 VSS power_in Ground supply pin.
48 VDD power_in Main digital supply, 1.71 V to 3.6 V.
49 EP passive Exposed pad (from the footprint; not named in the datasheet pin table).

Key specifications

Parameter Value
Manufacturer STMicroelectronics
Package UFQFPN-48(7x7)
Category Embedded Processors & Controllers
Pins 49

CAD (KiCad official)

  • Symbol: STM32L431CCU6
  • Footprint: Package_DFN_QFN:QFN-48-1EP_7x7mm_P0.5mm_EP5.15x5.15mm
  • 3D model: UFQFPN-48(7x7) (KiCad packages3D, STEP)
  • 3D model files: stm32l431ccu6-etched.step / stm32l431ccu6-etched.glb carry the MPN laser-etched on the die in a toggleable Adom.LaserEtch group (Fusion-ready); stm32l431ccu6.step / stm32l431ccu6.glb are the bare package body.

Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

  • Datasheet: STMicroelectronics datasheet (208 pp, sha256 71963de3cb899f8f, retrieved 2026-10-03, tier: lcsc)
  • Extractor: parts-factory 2.0.0 / extract_pins 0.3, primary claude-haiku-4-5-20251001 (text), consensus claude-sonnet-5-5 (agreed), guards: pin_guards 0.1: passed. Pins are checked against the footprint pad set and their cited datasheet pages before publish.
  • CAD: KiCad official libraries (CC-BY-SA 4.0).

Datasheet PDF