| Pin | Symbol | Type | Function (EN) |
|---|---|---|---|
| 1 | INT# | I/O | Multiplexed I/O & Peripheral Pin INT# (General) |
| 2 | RSTI | I/O | Multiplexed I/O & Peripheral Pin RSTI (General) |
| 3 | WR# | I/O | Multiplexed I/O & Peripheral Pin WR# (General) |
| 4 | V3 | Power | Regulated Power Output (V3 — 3.3V / 5.0V Standard Logic) |
| 5 | UEN | I/O | Multiplexed I/O & Peripheral Pin UEN (General) |
| 6 | CKO | I/O | Multiplexed I/O & Peripheral Pin CKO (General) |
| 7 | SLP | I/O | Multiplexed I/O & Peripheral Pin SLP (General) |
| 8 | A0 | I/O | Multiplexed I/O & Peripheral Pin A0 (General) |
| 9 | GND | GND | Ground Reference Pin (GND) |
| 10 | XI | I/O | Multiplexed I/O & Peripheral Pin XI (RTC/CLK) |
| 11 | XO | I/O | Multiplexed I/O & Peripheral Pin XO (RTC/CLK) |
| 12 | GND | GND | Ground Reference Pin (GND) |
| 13 | XI | I/O | Multiplexed I/O & Peripheral Pin XI (RTC/CLK) |
| 14 | XO | I/O | Multiplexed I/O & Peripheral Pin XO (RTC/CLK) |
| 15 | D0 | I/O | Multiplexed I/O & Peripheral Pin D0 (General) |
| 16 | D1 | I/O | Multiplexed I/O & Peripheral Pin D1 (General) |
| 17 | D2 | I/O | Multiplexed I/O & Peripheral Pin D2 (General) |
| 18 | SCS/D3 | I/O | Multiplexed I/O & Peripheral Pin SCS/D3 (General) |
| 19 | D4 | I/O | Multiplexed I/O & Peripheral Pin D4 (General) |
| 20 | SCK/D5 | I/O | Multiplexed I/O & Peripheral Pin SCK/D5 (SPI) |
| 21 | SDI/D6 | I/O | Multiplexed I/O & Peripheral Pin SDI/D6 (General) |
| 22 | SDO/D7 | I/O | Multiplexed I/O & Peripheral Pin SDO/D7 (General) |
| 23 | VCC | Power | Power Supply Input (VCC — 3.3V / 5.0V Standard Logic) |
| 24 | ACT# | I/O | Multiplexed I/O & Peripheral Pin ACT# (General) |
| 25 | RST | I/O | Multiplexed I/O & Peripheral Pin RST (General) |
| 26 | RST# | I/O | Multiplexed I/O & Peripheral Pin RST# (General) |
| 27 | CS# | I/O | Multiplexed I/O & Peripheral Pin CS# (General) |
| 28 | VCC | Power | Power Supply Input (VCC — 3.3V / 5.0V Standard Logic) |
| Designator / Replacement MPN | Value / Package | Function & PCB Layout Rule |
|---|---|---|
| N/A BOM | Per application circuit SOP-28-300mil | Size power & signal trace widths for rated load current following IPC-2221 clearance rules. |
Manufactured by WCH, the CH374S is housed in a SOP-28-300mil package with 28 pins and a 1.27 mm lead pitch. Key pins include: 1 (INT#: Multiplexed I/O & Peripheral Pin INT# (General)), 2 (RSTI: Multiplexed I/O & Peripheral Pin RSTI (General)), 3 (WR#: Multiplexed I/O & Peripheral Pin WR# (General)), 4 (V3: Regulated Power Output (V3 — 3.3V / 5.0V Standard Logic)), 5 (UEN: Multiplexed I/O & Peripheral Pin UEN (General)), 6 (CKO: Multiplexed I/O & Peripheral Pin CKO (General)).
Normalized from the official datasheet mechanical drawing per IPC-7351B (Density Level B Nominal), CH374S (SOP-28-300mil) has a nominal body envelope of 7.50 × 17.90 mm, pitch e = 1.27 mm, and 28 copper pads.
You can download the verified open-hardware (CERN-OHL-P-2.0) CAD library bundle for CH374S (WCH, SOP-28-300mil) 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.
| Pin # | Signal Name | Electrical Type | Functional Description & Design Notes |
|---|---|---|---|
| 1 | INT# | Digital_IO | Signal terminal INT# (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: INT#. Supported peripheral buses: General. |
| 2 | RSTI | Digital_IO | Signal terminal RSTI (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: RSTI. Supported peripheral buses: General. |
| 3 | WR# | Digital_IO | Signal terminal WR# (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: WR#. Supported peripheral buses: General. |
| 4 | V3 | Power_Out | Regulated power output rail (V3) operating in the 3.3V / 5.0V Standard Logic domain (Max rating: 5.5V). |
| 5 | UEN | Digital_IO | Signal terminal UEN (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: UEN. Supported peripheral buses: General. |
| 6 | CKO | Digital_IO | Signal terminal CKO (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: CKO. Supported peripheral buses: General. |
| 7 | SLP | Digital_IO | Signal terminal SLP (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: SLP. Supported peripheral buses: General. |
| 8 | A0 | Digital_IO | Signal terminal A0 (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: A0. Supported peripheral buses: General. |
| 9 | GND | GND | 0V electrical ground return terminal (GND) for internal core logic, I/O drivers, and analog sub-blocks. |
| 10 | XI | Digital_IO | Signal terminal XI (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: XI. Supported peripheral buses: RTC/CLK. |
| 11 | XO | Digital_IO | Signal terminal XO (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: XO. Supported peripheral buses: RTC/CLK. |
| 12 | GND | GND | 0V electrical ground return terminal (GND) for internal core logic, I/O drivers, and analog sub-blocks. |
| 13 | XI | Digital_IO | Signal terminal XI (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: XI. Supported peripheral buses: RTC/CLK. |
| 14 | XO | Digital_IO | Signal terminal XO (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: XO. Supported peripheral buses: RTC/CLK. |
| 15 | D0 | Digital_IO | Signal terminal D0 (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: D0. Supported peripheral buses: General. |
| 16 | D1 | Digital_IO | Signal terminal D1 (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: D1. Supported peripheral buses: General. |
| 17 | D2 | Digital_IO | Signal terminal D2 (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: D2. Supported peripheral buses: General. |
| 18 | SCS/D3 | Digital_IO | Signal terminal SCS/D3 (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: SCS/D3. Supported peripheral buses: General. |
| 19 | D4 | Digital_IO | Signal terminal D4 (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: D4. Supported peripheral buses: General. |
| 20 | SCK/D5 | Digital_IO | Signal terminal SCK/D5 (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: SPI. Supported peripheral buses: SPI. |
| 21 | SDI/D6 | Digital_IO | Signal terminal SDI/D6 (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: SDI/D6. Supported peripheral buses: General. |
| 22 | SDO/D7 | Digital_IO | Signal terminal SDO/D7 (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: SDO/D7. Supported peripheral buses: General. |
| 23 | VCC | Power_In | Primary positive power supply input (VCC) operating in the 3.3V / 5.0V Standard Logic domain (Max rating: 5.5V). |
| 24 | ACT# | Digital_IO | Signal terminal ACT# (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: ACT#. Supported peripheral buses: General. |
| 25 | RST | Digital_IO | Signal terminal RST (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: RST. Supported peripheral buses: General. |
| 26 | RST# | Digital_IO | Signal terminal RST# (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: RST#. Supported peripheral buses: General. |
| 27 | CS# | Digital_IO | Signal terminal CS# (I/O, 3.3V / 5.0V Standard Logic domain). Multiplexed alternate functions: CS#. Supported peripheral buses: General. |
| 28 | VCC | Power_In | Primary positive power supply input (VCC) operating in the 3.3V / 5.0V Standard Logic domain (Max rating: 5.5V). |