Mechanical Dimensions & Land Pattern (WLCSP-25(2.1x2.5))
Extracted from Datasheet & IPC-7351B NormalizedRecommended Companion BOM & Drop-In Equivalents
Passive external components per reference schematic and 1:1 pin-compatible alternatives| Designator / Replacement MPN | Value / Package | Function & PCB Layout Rule |
|---|---|---|
| N/A BOM | Per application circuit WLCSP-25(2.1x2.5) | Size power & signal trace widths for rated load current following IPC-2221 clearance rules. |
Technical Frequently Asked Questions (FAQ) — STM32L041E6Y6TR (WLCSP-25(2.1x2.5))
Quick answers covering Pinout, IPC-7351B Land Pattern dimensions, and CAD export formatsWhat is the Pinout and operating voltage specification of STM32L041E6Y6TR (WLCSP-25(2.1x2.5))?
Manufactured by ST, the STM32L041E6Y6TR is housed in a WLCSP-25(2.1x2.5) package with 25 pins and a 0.40 mm lead pitch, supporting a VCC supply range of 1.65 V to 3.6 V. Key pins include: A1 (PA13: Multiplexed I/O & Peripheral Pin PA13 (SWD/JTAG)), A2 (PA14: Multiplexed I/O & Peripheral Pin PA14 (UART, I2C, SWD/JTAG)), A3 (PB6: Multiplexed I/O & Peripheral Pin PB6 (UART, I2C)), A4 (PB7: Multiplexed I/O & Peripheral Pin PB7 (UART, I2C)), A5 (BOOT0: Input-Only Pin BOOT0 (General)), B1 (PA9: Multiplexed I/O & Peripheral Pin PA9 (UART, I2C, RTC/CLK)).
What are the IPC-7351B PCB Footprint dimensions for STM32L041E6Y6TR?
Normalized from the official datasheet mechanical drawing per IPC-7351B (Density Level B Nominal), STM32L041E6Y6TR (WLCSP-25(2.1x2.5)) has a nominal body envelope of 2.10 × 2.50 mm, pitch e = 0.40 mm, and 25 copper pads.
Where can I download KiCad (.kicad_mod, .kicad_sym), Fusion 360 (.lbr), and 3D STEP models for STM32L041E6Y6TR?
You can download the verified open-hardware (CERN-OHL-P-2.0) CAD library bundle for STM32L041E6Y6TR (ST, WLCSP-25(2.1x2.5)) directly on this page, including KiCad 8 Footprints (.kicad_mod), Schematic Symbols (.kicad_sym), Autodesk Fusion 360 / Eagle (.lbr), and 3D STEP AP214 / WebGL GLB models.
Static Reference Appendix: Pinout Table (25 pins) & STM32L041 Family VariantsExpand static table
| Pin # | Signal Name | Electrical Type | Functional Description & Design Notes |
|---|---|---|---|
| A1 | PA13 | Digital_IO | Signal terminal PA13 (I/O, 3.3V VDD (5V-Tolerant FT) domain). Multiplexed alternate functions: PA13. Supported peripheral buses: SWD/JTAG. |
| A2 | PA14 | Digital_IO | Signal terminal PA14 (I/O, 3.3V VDD (5V-Tolerant FT) domain). Multiplexed alternate functions: I2C1_SMBA. Supported peripheral buses: UART, I2C, SWD/JTAG. |
| A3 | PB6 | Digital_IO | Signal terminal PB6 (I/O, 3.3V VDD (5V-Tolerant FT) domain). Multiplexed alternate functions: I2C1_SCL. Supported peripheral buses: UART, I2C. |
| A4 | PB7 | Digital_IO | Signal terminal PB7 (I/O, 3.3V VDD (5V-Tolerant FT) domain). Multiplexed alternate functions: I2C1_SDA. Supported peripheral buses: UART, I2C. |
| A5 | BOOT0 | Digital_IO | Signal terminal BOOT0 (I, 3.3V VDD (Max 4.0V) domain). Multiplexed alternate functions: BOOT0. Supported peripheral buses: General. |
| B1 | PA9 | Digital_IO | Signal terminal PA9 (I/O, 3.3V VDD (5V-Tolerant FT) domain). Multiplexed alternate functions: I2C1_SCL. Supported peripheral buses: UART, I2C, RTC/CLK. |
| B2 | PB3 | Digital_IO | Signal terminal PB3 (I/O, 3.3V VDD (5V-Tolerant FT) domain). Multiplexed alternate functions: SPI1_SCK. Supported peripheral buses: SPI, PWM. |
| B3 | PA4 | Digital_IO | Signal terminal PA4 (I/O, 3.3V VDD (Max 4.0V) domain). Multiplexed alternate functions: SPI1_NSS. Supported peripheral buses: UART, SPI, ADC. |
| B4 | PA1 | Digital_IO | Signal terminal PA1 (I/O, 3.3V VDD (5V-Tolerant FT) domain). Multiplexed alternate functions: I2C1_SMBA. Supported peripheral buses: UART, I2C, ADC, PWM. |
| B5 | PC14 - OSC32_IN | Digital_IO | Signal terminal PC14 - OSC32_IN (I/O, 3.3V VDD (Max 4.0V) domain). Multiplexed alternate functions: PC14 - OSC32_IN. Supported peripheral buses: RTC/CLK. |
| C1 | PA8 | Digital_IO | Signal terminal PA8 (I/O, 3.3V VDD (5V-Tolerant FT) domain). Multiplexed alternate functions: PA8. Supported peripheral buses: UART, PWM, RTC/CLK. |
| C2 | PA10 | Digital_IO | Signal terminal PA10 (I/O, 3.3V VDD (5V-Tolerant FT) domain). Multiplexed alternate functions: I2C1_SDA. Supported peripheral buses: UART, I2C. |
| C3 | PA7 | Digital_IO | Signal terminal PA7 (I/O, 3.3V VDD (5V-Tolerant FT) domain). Multiplexed alternate functions: SPI1_MOSI. Supported peripheral buses: UART, SPI, ADC. |
| C4 | VDDA | Power_In | Primary positive power supply input (VDDA) operating in the 3.3V VDD (Max 4.0V) domain (Max rating: 4.0V). |
| C5 | PC15 - OSC32_ OUT | Digital_IO | Signal terminal PC15 - OSC32_ OUT (I/O, 3.3V VDD (Max 4.0V) domain). Multiplexed alternate functions: PC15 - OSC32_ OUT. Supported peripheral buses: RTC/CLK. |
| D1 | VDD | Power_In | Primary positive power supply input (VDD) operating in the 3.3V VDD (Max 4.0V) domain (Max rating: 4.0V). |
| D2 | PB1 | Digital_IO | Signal terminal PB1 (I/O, 3.3V VDD (5V-Tolerant FT) domain). Multiplexed alternate functions: SPI1_MOSI. Supported peripheral buses: UART, SPI, ADC, PWM. |
| D3 | PA5 | Digital_IO | Signal terminal PA5 (I/O, 3.3V VDD (Max 4.0V) domain). Multiplexed alternate functions: SPI1_SCK. Supported peripheral buses: SPI, ADC, PWM. |
| D4 | PA2 | Digital_IO | Signal terminal PA2 (I/O, 3.3V VDD (Max 4.0V) domain). Multiplexed alternate functions: PA2. Supported peripheral buses: UART, ADC, PWM, RTC/CLK. |
| D5 | NRST | Digital_IO | Active-low hardware reset terminal (NRST): pulling this pin Low resets the processor core and peripherals. |
| E1 | VSSA | GND | 0V electrical ground return terminal (VSSA) for internal core logic, I/O drivers, and analog sub-blocks. |
| E2 | PB0 | Digital_IO | Signal terminal PB0 (I/O, 3.3V VDD (5V-Tolerant FT) domain). Multiplexed alternate functions: SPI1_MISO. Supported peripheral buses: UART, SPI, ADC, PWM. |
| E3 | PA6 | Digital_IO | Signal terminal PA6 (I/O, 3.3V VDD (5V-Tolerant FT) domain). Multiplexed alternate functions: SPI1_MISO. Supported peripheral buses: UART, SPI, ADC. |
| E4 | PA3 | Digital_IO | Signal terminal PA3 (I/O, 3.3V VDD (5V-Tolerant FT) domain). Multiplexed alternate functions: PA3. Supported peripheral buses: UART, ADC, PWM. |
| E5 | PA0CK IN -_ | Digital_IO | Signal terminal PA0CK IN -_ (I/O, 3.3V VDD (Max 4.0V) domain). Multiplexed alternate functions: PA0CK IN -_. Supported peripheral buses: UART, ADC, PWM, RTC/CLK. |












