STM32L431RCT6TR from STMicroelectronics, in a LQFP-64(10x10). Pinout and pin descriptions extracted from the manufacturer datasheet by ds2sf; symbol, footprint, and 3D from KiCad-official CAD.

Pinout

Pin	Name	Type	Function
1	VBAT	power_in	Backup battery supply for RTC and 32x32-bit backup registers. Typical 1.55 V to 3.6 V; ~200 nA in VBAT mode.
2	PC13	bidirectional	GPIO PC13 (FT). Alt: EVENTOUT. Additional: RTC_TAMP1, RTC_TS, RTC_OUT, WKUP2.
3	PC14-OSC32_IN	bidirectional	GPIO PC14 / LSE 32 kHz oscillator input (OSC32_IN). Muxed via RCC.
4	PC15-OSC32_OUT	bidirectional	GPIO PC15 / LSE 32 kHz oscillator output (OSC32_OUT).
5	PH0-OSC_IN	bidirectional	GPIO PH0 / HSE crystal oscillator input (OSC_IN).
6	PH1-OSC_OUT	bidirectional	GPIO PH1 / HSE crystal oscillator output (OSC_OUT).
7	NRST	bidirectional	Bidirectional reset pin, active low. Internal pull-up; driven low by MCU on internal reset sources.
8	PC0	bidirectional	GPIO PC0 (FT_fa). Alt: LPTIM1_IN1, I2C3_SCL, LPUART1_RX, LPTIM2_IN1, EVENTOUT. Additional: ADC1_IN1.
9	PC1	bidirectional	GPIO PC1 (FT_fa). Alt: LPTIM1_OUT, I2C3_SDA, LPUART1_TX, EVENTOUT. Additional: ADC1_IN2.
10	PC2	bidirectional	GPIO PC2 (FT_a). Alt: LPTIM1_IN2, SPI2_MISO, EVENTOUT. Additional: ADC1_IN3.
11	PC3	bidirectional	GPIO PC3 (FT_a). Alt: LPTIM1_ETR, SPI2_MOSI, SAI1_SD_A, LPTIM2_ETR, EVENTOUT. Additional: ADC1_IN4.
12	VSSA/VREF-	power_in	Analog ground and negative ADC/DAC reference (tied together on this package).
13	VDDA/VREF+	power_in	Analog supply and positive ADC/DAC reference input, 1.62 V to 3.6 V.
14	PA0	bidirectional	GPIO PA0 (FT_a). Alt: TIM2_CH1, USART2_CTS, COMP1_OUT, SAI1_EXTCLK, TIM2_ETR, EVENTOUT. Additional: OPAMP1_VINP, COMP1_INM, ADC1_IN5, RTC_TAMP2, WKUP1.
15	PA1	bidirectional	GPIO PA1 (FT_a). Alt: TIM2_CH2, I2C1_SMBA, SPI1_SCK, USART2_RTS_DE, TIM15_CH1N, EVENTOUT. Additional: OPAMP1_VINM, COMP1_INP, ADC1_IN6.
16	PA2	bidirectional	GPIO PA2 (FT_a). Alt: TIM2_CH3, USART2_TX, LPUART1_TX, QUADSPI_BK1_NCS, COMP2_OUT, TIM15_CH1, EVENTOUT. Additional: COMP2_INM, ADC1_IN7, WKUP4, LSCO.
17	PA3	bidirectional	GPIO PA3 (TT_a). Alt: TIM2_CH4, USART2_RX, LPUART1_RX, QUADSPI_CLK, SAI1_MCLK_A, TIM15_CH2, EVENTOUT. Additional: OPAMP1_VOUT, COMP2_INP, ADC1_IN8.
18	VSS	power_in	Digital ground.
19	VDD	power_in	Digital supply, 1.71 V to 3.6 V.
20	PA4	bidirectional	GPIO PA4 (TT_a). Alt: SPI1_NSS, SPI3_NSS, USART2_CK, SAI1_FS_B, LPTIM2_OUT, EVENTOUT. Additional: COMP1_INM, COMP2_INM, ADC1_IN9, DAC1_OUT1.
21	PA5	bidirectional	GPIO PA5 (TT_a). Alt: TIM2_CH1, TIM2_ETR, SPI1_SCK, LPTIM2_ETR, EVENTOUT. Additional: COMP1_INM, COMP2_INM, ADC1_IN10, DAC1_OUT2.
22	PA6	bidirectional	GPIO PA6 (FT_a). Alt: TIM1_BKIN, SPI1_MISO, COMP1_OUT, USART3_CTS, LPUART1_CTS, QUADSPI_BK1_IO3, TIM16_CH1, EVENTOUT. Additional: ADC1_IN11.
23	PA7	bidirectional	GPIO PA7 (FT_a). Alt: TIM1_CH1N, SPI1_MOSI, QUADSPI_BK1_IO2, TIM17_CH1, EVENTOUT. Additional: COMP2_INP, ADC1_IN12.
24	PC4	bidirectional	GPIO PC4 (FT_a). Alt: USART3_TX, EVENTOUT. Additional: ADC1_IN13.
25	PC5	bidirectional	GPIO PC5 (FT_a). Alt: USART3_RX, EVENTOUT. Additional: WKUP5, ADC1_IN14.
26	PB0	bidirectional	GPIO PB0 (FT_a). Alt: TIM1_CH2N, SPI1_NSS, USART3_CK, QUADSPI_BK1_IO1, SAI1_EXTCLK, COMP1_OUT, EVENTOUT. Additional: ADC1_IN15.
27	PB1	bidirectional	GPIO PB1 (FT_a). Alt: TIM1_CH3N, USART3_RTS_DE, LPUART1_RTS_DE, QUADSPI_BK1_IO0, LPTIM2_IN1, EVENTOUT. Additional: ADC1_IN16.
28	PB2	bidirectional	GPIO PB2 (FT). Alt: RTC_OUT, LPTIM1_OUT, I2C3_SMBA, EVENTOUT.
29	PB10	bidirectional	GPIO PB10 (FT_f). Alt: TIM2_CH3, I2C2_SCL, SPI2_SCK, USART3_TX, LPUART1_RX, QUADSPI_CLK, SAI1_SCK_A, COMP1_OUT, EVENTOUT.
30	PB11	bidirectional	GPIO PB11 (FT_f). Alt: TIM2_CH4, I2C2_SDA, USART3_RX, LPUART1_TX, QUADSPI_BK1_NCS, COMP2_OUT, EVENTOUT.
31	VSS	power_in	Digital ground.
32	VDD	power_in	Digital supply, 1.71 V to 3.6 V.
33	PB12	bidirectional	GPIO PB12 (FT_fa). Alt: TIM1_BKIN, SPI2_NSS, USART3_CK, LPUART1_RTS_DE, SAI1_FS_A, TSC_G1_IO1, EVENTOUT. Additional: COMP2_INP.
34	PB13	bidirectional	GPIO PB13 (FT_fa). Alt: TIM1_CH1N, I2C2_SCL, SPI2_SCK, USART3_CTS, LPUART1_CTS, SAI1_SCK_A, TSC_G1_IO2, EVENTOUT. Additional: COMP2_INM.
35	PB14	bidirectional	GPIO PB14 (FT_fa). Alt: TIM1_CH2N, I2C2_SDA, SPI2_MISO, USART3_RTS_DE, SAI1_MCLK_A, TSC_G1_IO3, TIM15_CH1, EVENTOUT. Additional: COMP2_INP.
36	PB15	bidirectional	GPIO PB15 (FT_fa). Alt: RTC_REFIN, TIM1_CH3N, SPI2_MOSI, SAI1_SD_A, TSC_G1_IO4, TIM15_CH2, EVENTOUT. Additional: COMP2_INM.
37	PC6	bidirectional	GPIO PC6 (FT). Alt: TSC_G4_IO1, EVENTOUT.
38	PC7	bidirectional	GPIO PC7 (FT). Alt: TSC_G4_IO2, EVENTOUT.
39	PC8	bidirectional	GPIO PC8 (FT). Alt: TSC_G4_IO3, EVENTOUT.
40	PC9	bidirectional	GPIO PC9 (FT). Alt: TIM8_BKIN2, I2C3_SDA, SAI1_D_A, TSC_G4_IO4, EVENTOUT.
41	PA8	bidirectional	GPIO PA8 (FT). Alt: MCO, TIM1_CH1, USART1_CK, SAI1_SCK_A, LPTIM2_OUT, SWPMI1_IO1, EVENTOUT.
42	PA9	bidirectional	GPIO PA9 (FT_f). Alt: TIM1_CH2, I2C1_SCL, USART1_TX, SAI1_FS_A, TIM15_BKIN, EVENTOUT.
43	PA10	bidirectional	GPIO PA10 (FT_f). Alt: TIM1_CH3, I2C1_SDA, USART1_RX, SAI1_SD_A, EVENTOUT.
44	PA11	bidirectional	GPIO PA11 (FT). Alt: TIM1_CH4, TIM1_BKIN2, SPI1_MISO, USART1_CTS, CAN1_RX, EVENTOUT.
45	PA12	bidirectional	GPIO PA12 (FT). Alt: TIM1_ETR, SPI1_MOSI, USART1_RTS_DE, CAN1_TX, EVENTOUT.
46	PA13	bidirectional	GPIO PA13 (FT). Default SWDIO after reset. Alt: JTMS-SWDIO, IR_OUT, SWPMI1_TX, EVENTOUT.
47	VSS	power_in	Digital ground.
48	VDD	power_in	Digital supply, 1.71 V to 3.6 V.
49	PA14	bidirectional	GPIO PA14 (FT). Default SWCLK after reset. Alt: JTCK-SWCLK, LPTIM1_OUT, SWPMI1_RX, EVENTOUT.
50	PA15	bidirectional	GPIO PA15 (FT). Default JTDI after reset. Alt: JTDI, TIM2_CH1, TIM2_ETR, USART2_RX, USART3_RTS_DE, SPI1_NSS, SPI3_NSS, TSC_G3_IO1, SWPMI1_SUSPEND, EVENTOUT.
51	PC10	bidirectional	GPIO PC10 (FT). Alt: SPI3_SCK, USART3_TX, LPUART1_TX, SAI1_D_A, TSC_G3_IO2, EVENTOUT.
52	PC11	bidirectional	GPIO PC11 (FT). Alt: SPI3_MISO, USART3_RX, LPUART1_RX, TSC_G3_IO3, EVENTOUT.
53	PC12	bidirectional	GPIO PC12 (FT). Alt: SPI3_MOSI, USART3_CK, SAI1_D_A, TSC_G3_IO4, EVENTOUT.
54	PD2	bidirectional	GPIO PD2 (FT). Alt: TIM3_ETR, USART3_RTS_DE, EVENTOUT.
55	PB3	bidirectional	GPIO PB3 (FT). Default JTDO/TRACESWO after reset. Alt: JTDO-TRACESWO, TIM2_CH2, SPI1_SCK, SPI3_SCK, USART1_RTS_DE, SAI1_SCK_B, EVENTOUT.
56	PB4	bidirectional	GPIO PB4 (FT). Default NJTRST after reset. Alt: NJTRST, TIM3_CH1, SPI1_MISO, SPI3_MISO, USART1_CTS, TSC_G2_IO1, SAI1_MCLK_B, TIM17_BKIN, EVENTOUT.
57	PB5	bidirectional	GPIO PB5 (FT). Alt: LPTIM1_IN1, TIM3_CH2, I2C1_SMBA, SPI1_MOSI, SPI3_MOSI, USART1_CK, CAN2_RX, TSC_G2_IO2, SAI1_SD_B, TIM16_BKIN, EVENTOUT.
58	PB6	bidirectional	GPIO PB6 (FT_f). Alt: LPTIM1_ETR, TIM4_CH1, I2C1_SCL, USART1_TX, CAN2_TX, TSC_G2_IO3, SAI1_FS_B, TIM16_CH1N, EVENTOUT.
59	PB7	bidirectional	GPIO PB7 (FT_f). Alt: LPTIM1_IN2, TIM4_CH2, I2C1_SDA, USART1_RX, TSC_G2_IO4, TIM17_CH1N, EVENTOUT.
60	PH3-BOOT0	bidirectional	GPIO PH3 muxed with BOOT0 boot-mode select input. Sampled at reset to choose the boot source (Main Flash, System memory bootloader, SRAM).
61	PB8	bidirectional	GPIO PB8 (FT_f). Alt: TIM4_CH3, TIM16_CH1, I2C1_SCL, CAN1_RX, SAI1_MCLK_A, SDMMC1_D4, EVENTOUT.
62	PB9	bidirectional	GPIO PB9 (FT_f). Alt: TIM4_CH4, TIM17_CH1, I2C1_SDA, SPI2_NSS, CAN1_TX, IR_OUT, SAI1_FS_A, SDMMC1_D5, EVENTOUT.
63	VSS	power_in	Digital ground.
64	VDD	power_in	Digital supply, 1.71 V to 3.6 V.

Key specifications

Parameter	Value
Manufacturer	STMicroelectronics
Package	LQFP-64(10x10)
Category	MCU
Pins	64

Ordering variants

Same part, different packaging or reel option.

STM32L431RCT6TR
STM32L431RCT6TRRCY6TR
STM32L431RCT6TRVCT6
STM32L431RCT6TRVCI6
STM32L431RCT6TRCCT6
STM32L431RCT6TRCCU6
STM32L431RCT6TRCCY6TR
STM32L431RCT6TRKCU6
STM32L431RCT6TRRCI6

CAD (KiCad official)

Symbol: STM32L431RCT6TR
Footprint: Package_QFP:LQFP-64_10x10mm_P0.5mm
3D model: LQFP-64(10x10) (KiCad packages3D, STEP)

Provenance

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

Datasheet: STMicroelectronics datasheet (208 pp, sha256 71963de3cb899f8f, retrieved 2026-08-17, tier: manufacturer)
Extractor: ds2sf (Claude). Every pin and dimension is cited to a datasheet page; it refuses to fabricate.
CAD: KiCad official libraries (CC-BY-SA 4.0).

Datasheet PDF