Behavioural mixed-signal modelCH340Cch340c
CH340C USB-UART (to the PC)
USB-to-UART bridge with internal oscillator: the serial port of the PC. Bytes arriving on RXD appear in the part's terminal, typed text leaves on TXD (8N1, any standard baud rate; the bridge follows the host). Wire RXD to the board's TX and TXD to its RX (crossed). VCC 5 V from USB with V3 to 100 nF, or VCC = V3 = 3.3 V. The USB link to the PC (UD+ / UD−) is abstracted: plugged in while VCC is powered.
Key data
- Category
- Interfaces
- Simulation model
- Behavioural mixed-signal model
- Manufacturer part number
- CH340C
- Reference prefix
- U
- Pins
- 15
- Land pattern
- SOIC-16_3.9x9.9mm_P1.27mm
Simulation model
A behavioural model implements the interface of the chip (registers, protocol, timing) at its pins. The pins are connected to the analog circuit like CMOS pins.
- Model
- ch340c
- Supply pins
- VCC / GND
Pins 15
| Pin | Name | Use |
|---|---|---|
| VCC | VCCSupply pin | Supply input: decouple with 100 nF close to the pin |
| V3 | V3Supply pin | Supply input: decouple with 100 nF close to the pin |
| UD+ | UD+I/O pin | General-purpose I/O: LEDs (with series resistor), buttons (with pull-up) |
| UD- | UD-I/O pin | General-purpose I/O: LEDs (with series resistor), buttons (with pull-up) |
| R232 | R232Input pin | Logic input: never leave open (tie unused inputs to VCC or GND) |
| NC | NCPassive pin | Not connected: leave open |
| TXD | TXDOutput pin | Logic output: drives the next input; do not tie outputs together |
| RXD | RXDInput pin | Logic input: never leave open (tie unused inputs to VCC or GND) |
| CTS_N | CTS#Input pin | Logic input: never leave open (tie unused inputs to VCC or GND) |
| DSR_N | DSR#Input pin | Logic input: never leave open (tie unused inputs to VCC or GND) |
| RI_N | RI#Input pin | Logic input: never leave open (tie unused inputs to VCC or GND) |
| DCD_N | DCD#Input pin | Logic input: never leave open (tie unused inputs to VCC or GND) |
| DTR_N | DTR#Output pin | Logic output: drives the next input; do not tie outputs together |
| RTS_N | RTS#Output pin | Logic output: drives the next input; do not tie outputs together |
| GND | GNDGround pin | Ground |
PCB
Verified land pattern
SOIC-16_3.9x9.9mm_P1.27mm| Package | Land pattern | Status | Source |
|---|---|---|---|
| SOIC-16 · CH340C | SOIC-16_3.9x9.9mm_P1.27mm | Verified land pattern | KiCad 10.0.7: symbol Interface_USB:CH340C, footprint Package_SO:SOIC-16_3.9x9.9mm_P1.27mm |