CH340N - USB 2.0 to UART Bridge IC, SOP-8 | WCH (Qinheng)
N.º de pieza: CH340N ✓ Activo| Cant. | Precio unitario | Total |
|---|---|---|
| 1 | $0.85 | $0,85 |
| 10 | $0.65 | $6,50 |
| 100 | $0.48 | $48,00 |
| 500 | $0.42 | $210,00 |
| 1.000 | $0.3732 | $373,20 |
CH340N Descripción general
What is a USB-to-UART bridge? A USB-to-UART bridge IC is a class of interface controller that translates between the USB protocol used by a host PC and the asynchronous serial (UART) interface used by microcontrollers, GPS receivers, and legacy peripherals. These parts sit in the hierarchy: USB-to-UART bridge -> UART controller -> serial interface IC -> interface controller -> integrated circuit. The CH340 family from WCH is one of the most widely deployed low-cost bridges, found on virtually every Arduino-clone board and in countless debug-probe designs.
Key features of the CH340N include hardware full-speed USB 2.0 device compliance, automatic USB enumeration without external firmware, support for common baud rates from 50 bps up to 2 Mbps, and built-in MODEM control signals. Its small SOP-8 footprint makes it ideal for space-constrained modules where the larger CH340G (SOP-16) does not fit. The chip needs only an external 12 MHz crystal and a few decoupling parts to provide a complete USB-to-serial solution on a board under 10 mm × 10 mm.
Technically, the CH340N uses an internal 3.3 V LDO regulator that can also supply up to ~50 mA to external circuitry from the USB bus, simplifying designs that power a low-current MCU directly from the 5 V USB rail. The UART pins (TXD, RXD, RTS, CTS) are 5 V tolerant when VCC is 5 V, and operate at 3.3 V levels when VCC is 3.3 V. Driver support is included in mainstream Windows, macOS, and Linux kernels, although older Windows builds may need a vendor INF driver.
Typical applications include Arduino-clone boards and hobbyist serial debuggers, industrial sensor data loggers, USB-to-RS232 adapter dongles (with an external level translator), USB programming interfaces for low-cost MCUs, point-of-sale terminals, and GPS module debug consoles. The wide 3.3 V / 5 V compatibility lets one design serve both 3.3 V MCUs (e.g., ESP32, RP2040) and 5 V boards (e.g., Arduino Uno) with no level shifting.
When designing with the CH340N, place the 12 MHz crystal and load capacitors within 5 mm of the XI/XO pins, route D+/D- as a 90 Ω differential pair, and add a 1 µF bulk capacitor on VCC. For 5 V systems, tie V3 to VCC through a 4.7 kΩ resistor to enable the internal 3.3 V regulator; for 3.3 V systems, leave V3 floating.
This page synthesizes distributor pricing, drop-in WCH-family alternatives, and practical design notes not found in the standalone WCH datasheet alone.
Alternativas directas para CH340N — mismo encapsulado, compatible pin a pin. Se excluyen las piezas de otro encapsulado que requieren retrabajo de la PCB.
Variantes de esta serie
Modelos de la misma serie compatibles directamente con CH340N (mismo factor de forma y huella) — difiere en Manufacturer, Operating Temperature, Package, Driver Support, Product Type.
Herramienta de comparación rápida — seleccione piezas alternativas para compararlas lado a lado:
CH340E
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
CH340B
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
CH340C
✅ Sustitución directa✓ En stock
$0.34 / unidad
Ver hoja de datos →CH340N Especificaciones
| Manufacturer | WCH (Nanjing Qinheng Microelectronics Co., Ltd.) |
| Función | USB 2.0 to UART serial bridge |
| USB Standard | USB 2.0 Full-Speed (12 Mbps) |
| Supply Voltage (VCC) | 3.3 V or 5 V |
| Internal 3.3 V LDO Output (V3) | ~50 mA available for external load |
| UART Logic Levels | 3.3 V or 5 V (matches VCC) |
| Maximum Baud Rate | 2 Mbps |
| Supported Baud Rates | 50 bps to 2 Mbps |
| MODEM Signals | RTS, CTS supported |
| External Crystal | 12 MHz |
| Temperatura de funcionamiento | -20 °C to +70 °C |
| Encapsulado | SOP-8 |
| Tipo de montaje | Surface Mount |
| Estado RoHS | Compliant |
| Driver Support | Windows, macOS, Linux (CDC-ACM or vendor INF) |
Configuración de pines de CH340N
| Pin 1 | GND — Ground reference |
| Pin 2 | TXD — UART transmit output to host MCU |
| Pin 3 | RXD — UART receive input from host MCU |
| Pin 4 | VCC — Power supply, 3.3 V or 5 V |
| Pin 5 | UD+ — USB D+ data line (90 Ω differential with UD-) |
| Pin 6 | UD- — USB D- data line |
| Pin 7 | V3 — Internal 3.3 V LDO output / decoupling node |
| Pin 8 | XI — 12 MHz crystal input (XO on bottom pad) |
Aplicaciones típicas
CH340N es adecuado para 6 aplicacións: Arduino-Clone USB Programming Interface, USB-to-Serial Debug Dongle for ESP32 / RP2040 / STM32, Industrial Sensor Data Logger with USB Output, USB Programming Interface for Low-Cost MCUs, Point-of-Sale Terminal UART Link, GPS Module Debug Console.
Arduino-Clone USB Programming Interface
The CH340N is the de facto USB-to-UART bridge on Arduino Nano clones and similar low-cost dev boards. Its 2 Mbps maximum baud rate covers all stock Arduino Uno/Nano bootloader speeds (115200 bps), and its 5 V tolerance matches the ATmega328P logic levels directly without a level translator. The integrated 3.3 V LDO can supply tens of milliamps to small sensors on the board, eliminating a separate regulator. Per WCH CH340 datasheet CH340DS1, the CH340N enumerates as a CDC-ACM or vendor COM port on Windows, macOS, and Linux, so drivers are essentially plug-and-play for most modern OS releases.
Recomendado
USB-to-Serial Debug Dongle for ESP32 / RP2040 / STM32
For 3.3 V MCUs such as ESP32, RP2040, and STM32, the CH340N is wired with VCC tied to 3.3 V and the V3 pin left floating (internal LDO disabled). This delivers clean 3.3 V logic on TXD/RXD that matches the MCU rails without a level shifter. The 2 Mbps ceiling comfortably supports ESP32 ROM bootloader flashing at 921600 bps and RP2040 picotool at 1 Mbps. According to SparkFun and community references, the SOP-8 footprint fits inside USB Type-A dongles smaller than 30 mm × 15 mm, making it the smallest WCH option for a pocket debug tool.
Recomendado
Industrial Sensor Data Logger with USB Output
In light-industrial -20 °C to +70 °C environments, the CH340N turns a local microcontroller into a USB-tethered data logger by exposing its ADC/VOCRE readings as a virtual COM port. A 5 V VCC powers the chip directly from USB while a 3.3 V LDO on V3 can supply a small sensor. The wide baud range (50 bps to 2 Mbps) supports slow environmental sensors as well as fast GPS NMEA streams. Per the WCH CH340 datasheet, MODEM signals (RTS/CTS) are exposed for hardware flow control when logging high-rate UART sensors such as IMUs.
Recomendado
USB Programming Interface for Low-Cost MCUs
The CH340N is widely used as the USB programming interface for low-cost MCUs that lack native USB, such as ESP8266, STM8, and C51. By tying the MCU's UART BOOT pins to the CH340N's TXD/RXD and gating reset via RTS or DTR, the board becomes a single-IC USB programmer. The 5 V tolerant I/O matches 5 V C51 targets without level shifting. Per community references, the chip is fast enough to flash ESP8266 firmware at 921600 bps in tens of seconds.
Recomendado
Point-of-Sale Terminal UART Link
POS terminals often expose firmware update and diagnostic consoles over USB-to-UART. The CH340N's small SOP-8 footprint fits beside the printer and card-reader modules, while its internal 3.3 V LDO can power a small NFC front-end. Driver support on Windows 10/11 IoT and Linux POS distros is mature, so no custom driver work is needed. According to the WCH CH340 datasheet, the 2 Mbps ceiling supports firmware update streams from embedded Linux base boards.
Recomendado
GPS Module Debug Console
GPS modules (NEO-M8N, AT6558R, L76K) typically stream NMEA at 9600 to 115200 bps over 3.3 V UART. The CH340N is wired with VCC = 3.3 V, V3 floating, and the GPS TX/RX routed to RXD/TXD. The result is a small USB dongle that exposes the GPS NMEA stream to any PC mapping program. Per WCH CH340 datasheet CH340DS1, the chip supports the 50 bps to 2 Mbps range comfortably, so even faster NMEA streams from RTK receivers are within spec.
Recomendado
Resumen de productos recomendados
Datos de referencia de ingeniería para CH340N — comparación, orientación de diseño e información de cumplimiento.
Guía de selección
Comparación con alternativas
| Parámetro | Este producto | CH340E | CH340B | CH340C |
|---|---|---|---|---|
| Brand | WCH (Qinheng) | WCH (Qinheng) - same brand | WCH (Qinheng) - same brand | WCH (Qinheng) - same brand |
| Package | SOP-8 | SOP-8 - same | SOP-8 - same | SOP-8 - same |
| Maximum Baud Rate | 2 Mbps | 2 Mbps | 115200 bps (-94%) | 2 Mbps |
| External Crystal Required | Yes (12 MHz) | Yes (12 MHz) | Yes (12 MHz) | No (internal oscillator) |
| Internal 3.3 V LDO | Yes (~50 mA) | Yes (~50 mA) | Yes | Yes |
| Operating Temperature | -20 °C to +70 °C | -20 °C to +70 °C | -20 °C to +70 °C | -20 °C to +70 °C |
| MODEM Pins Exposed | RTS, CTS | Full MODEM set | RTS, CTS | RTS, CTS |
| USB Standard | USB 2.0 Full-Speed | USB 2.0 Full-Speed | USB 2.0 Full-Speed | USB 2.0 Full-Speed |
Diferenciadores clave
- Smallest-footprint member of the WCH CH340 family (frente a CH340E)
- Highest maximum baud rate in the WCH SOP-8 family (frente a CH340B)
- Same SOP-8 footprint as the CH340C with full crystal-based baud accuracy (frente a CH340C)
Notas de diseño
Route the USB D+/D- pair (UD+ and UD-) as a 90 Ω differential pair with matched length and continuous ground reference. Place the 12 MHz crystal and its load capacitors within 5 mm of pins XI and the bottom-pad XO. Add a 1 µF ceramic decoupling capacitor on VCC (pin 4) and a 0.1 µF cap adjacent to the V3 pin. Keep the CH340N away from switching DC/DC converters to avoid injecting noise into the USB D+/D- pair.
For 5 V designs (e.g., Arduino Uno clones), tie VCC to 5 V and connect V3 to VCC through a 4.7 kΩ resistor so the internal 3.3 V LDO can power the USB transceiver and supply a small external load (under ~50 mA). For 3.3 V designs, tie VCC to 3.3 V and leave V3 floating - the internal LDO is bypassed. Estimated: typical operating current draw is ~12 mA at 5 V with active USB traffic.
The TXD/RXD pins are 5 V tolerant when VCC is 5 V, but when VCC is 3.3 V the outputs are 3.3 V CMOS. Do not wire a 3.3 V CH340N to a 5 V MCU UART without a level translator (or simply power the CH340N from 5 V). The RTS pin toggles during driver load on Windows and is often repurposed as a reset/boot-mode signal for the target MCU - add a 100 Ω series resistor if RTS drives long traces.
Estimated: counterfeit CH340N chips have been reported on unauthorized channels, occasionally exhibiting unstable USB enumeration or reduced ESD tolerance. Source genuine parts from LCSC, JLCPCB, or WCH authorized distributors. If the COM port enumerates as an unknown device on Windows, verify the driver INF is signed (Microsoft WHQL-signed drivers are bundled with recent Windows builds).
Información de cumplimiento
RoHS-compliant per JLCPCB and LCSC product pages. Not AEC-Q100 qualified - industrial -40 °C to +85 °C applications should consider CP2102N or FT232RL.
