Mechanical Dimensions & Land Pattern (QFN-28(4x4))
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 QFN-28(4x4) | Size power & signal trace widths for rated load current following IPC-2221 clearance rules. |
Technical Frequently Asked Questions (FAQ) — CH32V305GBU6 (QFN-28(4x4))
Quick answers covering Pinout, IPC-7351B Land Pattern dimensions, and CAD export formatsWhat is the Pinout and operating voltage specification of CH32V305GBU6 (QFN-28(4x4))?
Manufactured by WCH, the CH32V305GBU6 is housed in a QFN-28(4x4) package with 29 pins and a 0.50 mm lead pitch. Key pins include: 1 (VBAT: Power Supply Input (VBAT — 3.3V / 5.0V Standard Logic)), 2 (OSC_OUT/PD1: Multiplexed I/O & Peripheral Pin OSC_OUT/PD1 (RTC/CLK)), 3 (NRST: System Enable & Hardware Reset (NRST)), 4 (PC2: Multiplexed I/O & Peripheral Pin PC2 (UART, ADC, PWM)), 5 (PC3: Multiplexed I/O & Peripheral Pin PC3 (UART, ADC)), 6 (OSC_OUT: Multiplexed I/O & Peripheral Pin OSC_OUT (RTC/CLK)).
What are the IPC-7351B PCB Footprint dimensions for CH32V305GBU6?
Normalized from the official datasheet mechanical drawing per IPC-7351B (Density Level B Nominal), CH32V305GBU6 (QFN-28(4x4)) has a nominal body envelope of 4.00 × 4.00 mm, pitch e = 0.50 mm, and 29 copper pads plus a central exposed thermal pad (EPAD) of 2.80 × 2.80 mm with a 60% IPC-7525 windowed solder paste grid.
Where can I download KiCad (.kicad_mod, .kicad_sym), Fusion 360 (.lbr), and 3D STEP models for CH32V305GBU6?
You can download the verified open-hardware (CERN-OHL-P-2.0) CAD library bundle for CH32V305GBU6 (WCH, QFN-28(4x4)) 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 (29 pins) & CH32V208 / CH32V305 / CH32V307 Family VariantsExpand static table
| Pin # | Signal Name | Electrical Type | Functional Description & Design Notes |
|---|---|---|---|
| 1 | VBAT | Power_In | Primary positive power supply input (VBAT) operating in the 3.3V / 5.0V Standard Logic domain (Max rating: 5.5V). |
| 2 | OSC_OUT/PD1 | Digital_IO | Signal terminal OSC_OUT/PD1 (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: OSC_OUT/PD1. Supported peripheral buses: RTC/CLK. |
| 3 | NRST | Digital_IO | Active-low hardware reset terminal (NRST): pulling this pin Low resets the processor core and peripherals. |
| 4 | PC2 | Digital_IO | Signal terminal PC2 (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: PC2. Supported peripheral buses: UART, ADC, PWM. |
| 5 | PC3 | Digital_IO | Signal terminal PC3 (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: PC3. Supported peripheral buses: UART, ADC. |
| 6 | OSC_OUT | Digital_IO | Signal terminal OSC_OUT (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: OSC_OUT. Supported peripheral buses: RTC/CLK. |
| 7 | PA1(15) | Digital_IO | Signal terminal PA1(15) (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: PA1(15). Supported peripheral buses: UART, ADC, PWM. |
| 8 | PA5/SPI1SCK | Digital_IO | Signal terminal PA5/SPI1SCK (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: PA5/SPI1SCK. Supported peripheral buses: SPI. |
| 9 | PA6/SPI1MISO | Digital_IO | Signal terminal PA6/SPI1MISO (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: PA6/SPI1MISO. Supported peripheral buses: SPI. |
| 10 | PA7/SPI1MOSI | Digital_IO | Signal terminal PA7/SPI1MOSI (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: PA7/SPI1MOSI. Supported peripheral buses: SPI. |
| 11 | PB10/UART3TX/I2C2SCL | Digital_IO | Signal terminal PB10/UART3TX/I2C2SCL (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: PB10/UART3TX/I2C2SCL. Supported peripheral buses: UART, I2C. |
| 12 | PB11/UART3RX/I2C2SDA | Digital_IO | Signal terminal PB11/UART3RX/I2C2SDA (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: PB11/UART3RX/I2C2SDA. Supported peripheral buses: UART, I2C. |
| 13 | PB12/SPI2NSS/CAN2RX | Digital_IO | Signal terminal PB12/SPI2NSS/CAN2RX (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: PB12/SPI2NSS/CAN2RX. Supported peripheral buses: SPI, CAN. |
| 14 | IO16 | Digital_IO | GPIO16 / RTC_GPIO16 / U0CTS / ADC2_CH5 / XTAL_32K_N |
| 15 | PB14/SPI2MISO/UART3RTS | Digital_IO | Signal terminal PB14/SPI2MISO/UART3RTS (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: PB14/SPI2MISO/UART3RTS. Supported peripheral buses: UART, SPI. |
| 16 | PB15/SPI2MOSI/UART1TX2 | Digital_IO | Signal terminal PB15/SPI2MOSI/UART1TX2 (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: PB15/SPI2MOSI/UART1TX2. Supported peripheral buses: UART, SPI. |
| 17 | PA3 | Digital_IO | Signal terminal PA3 (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: PA3. Supported peripheral buses: UART, ADC, PWM. |
| 18 | V_SS4 | Digital_IO | Signal terminal V_SS4 (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: V_SS4. Supported peripheral buses: General. |
| 19 | V_DD4 | Digital_IO | Signal terminal V_DD4 (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: V_DD4. Supported peripheral buses: General. |
| 20 | PA4 | Digital_IO | Signal terminal PA4 (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: SPI1_NSS. Supported peripheral buses: UART, SPI, ADC, DAC, PWM. |
| 21 | PA5(15) | Digital_IO | Signal terminal PA5(15) (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: PA5(15). Supported peripheral buses: DAC. |
| 22 | PA6 | Digital_IO | Signal terminal PA6 (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: PA6. Supported peripheral buses: ADC, PWM. |
| 23 | PA7 | Digital_IO | Signal terminal PA7 (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: SPI1_MOSI. Supported peripheral buses: SPI, PWM. |
| 24 | IO13 | Digital_IO | GPIO13 / RTC_GPIO13 / TOUCH13 / ADC2_CH2 / FSPIQ |
| 25 | IO14 | Digital_IO | GPIO14 / RTC_GPIO14 / TOUCH14 / ADC2_CH3 / FSPIWP |
| 26 | PD2/UART5RX/SD_CMD | Digital_IO | Signal terminal PD2/UART5RX/SD_CMD (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: PD2/UART5RX/SD_CMD. Supported peripheral buses: UART. |
| 27 | PB6/USB2DM/UART1TX1 | Digital_IO | Signal terminal PB6/USB2DM/UART1TX1 (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: PB6/USB2DM/UART1TX1. Supported peripheral buses: USB, UART. |
| 28 | PB7/USB2DP/UART1RX1 | Digital_IO | Signal terminal PB7/USB2DP/UART1RX1 (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: PB7/USB2DP/UART1RX1. Supported peripheral buses: USB, UART. |
| 29 | GND | GND | 0V electrical ground return terminal (GND) for internal core logic, I/O drivers, and analog sub-blocks. |









