CH343 - 6Mbps USB to Serial UART Chip | WCH
料号： CH343 ✓ 量产中| 数量 | 单价 | 小计 |
|---|---|---|
| 1 | $0.9 | $0.90 |
| 10 | $0.82 | $8.20 |
| 100 | $0.74 | $74.00 |
| 500 | $0.68 | $340.00 |
| 1,000 | $0.62 | $620.00 |
CH343 概述
A USB-to-UART bridge is a type of interface converter IC in the broader USB controller hierarchy: it enumerates as a USB communications device on the host and exposes a standard COM port, allowing legacy serial peripherals, MCUs, and programmers to connect to modern computers that no longer provide RS-232 ports. Bridges like the CH343 sit between USB physical-layer controllers and UART protocol devices in the system chain.
Key features include 6 Mbps maximum baud rate (significantly faster than the 1-2 Mbps of typical competitors such as CH340 or CP2102), serial signal levels configurable for 5V, 3.3V, 2.5V, or 1.8V logic via the VIO supply, an integrated crystal oscillator that removes the need for an external crystal, and common MODEM handshake signals for hardware flow control.
Architecturally, the CH343 contains a USB full-speed transceiver, an integrated USB protocol engine, and built-in firmware that emulates a standard asynchronous serial interface. On Windows, the chip works with the operating-system built-in CDC class driver or the vendor high-speed VCP driver, so most existing serial applications run without modification. Dual-supply operation allows VBUS powering of the chip while the MCU side runs from an independent 5V, 3.3V, 2.5V, or 1.8V rail.
Typical applications include MCU programming and debugging adapters, embedded development boards (the chip is used on ESP32-class and Waveshare USB-UART boards), industrial equipment serial-port upgrades, and point-of-sale or instrumentation links.
Design consideration: connect the CFG pin appropriately to select CDC or VCP behavior, and keep the VIO level matched to the target MCU to avoid level-shifting damage; RXD/TXD are the only mandatory cross-connections in simple links.
This page synthesizes distributor pricing, drop-in family alternatives, and practical design notes not found in the manufacturer datasheet, with data verified as of 2026-10-20.
直接替换替代料： CH343 ——相同封装，引脚兼容。需要 PCB 改动的不同封装料号已排除。
快速对比工具——选择替代料号进行并排对比：
CH343G
✅ 直接替换 ⚠️ 规格未核验📋 参考替代料（不在目录中）
CH343P
✅ 直接替换📋 参考替代料（不在目录中）
CH343C
✅ 直接替换📋 参考替代料（不在目录中）
CH343 规格参数
| 功能 | USB to high-speed asynchronous serial UART converter |
| Maximum Baud Rate | 6 Mbps |
| Baud Rate Adaptation | Automatic identification, 115200 bps and below |
| VIO Logic Levels | 5 V / 3.3 V / 2.5 V / 1.8 V |
| Supply Voltage (VCC) | 3.3 V / 5 V |
| USB Interface | USB 2.0 full-speed |
| Integrated Crystal Oscillator | Yes (no external crystal required) |
| MODEM Signals | Common MODEM handshake signals supported |
| Driver Support | OS built-in CDC driver or vendor high-speed VCP driver |
| 工作温度 | -40C to +85C |
| Package (CH343G variant) | SOP-16 |
| 安装类型 | Surface Mount |
| Applications | Serial port expansion, MCU-to-USB upgrade |
| Power Modes | Single supply (VBUS) or dual power supply mode |
| Typical Unit Price | 0.7342 USD (LCSC, as of 2026-10-20) |
| RoHS 状态 | Compliant |
CH343 sop-16 引脚配置指南
CH343（sop-16 封装）的引脚配置。 引脚编号、功能和连接图在制造商数据手册中定义。请参阅该手册以了解确切的封装尺寸和焊接指南。
暂无详细引脚数据： CH343.
请参阅 数据手册 以查看完整引脚配置。
典型应用
CH343 适用于 6 应用s: MCU Programming and Debugging Adapters, Embedded Development Boards, Industrial Equipment Serial Port Upgrade, USB-to-UART Adapter Cables and Dongles, Point-of-Sale and Instrumentation Links, IoT Gateways and Smart Home Hubs.
MCU Programming and Debugging Adapters
The CH343 is a natural fit for USB-to-TTL programming adapters for ESP32, ESP8266, and STM32 bootloaders because its 6 Mbps maximum baud rate cuts firmware download time versus 2 Mbps-class bridges, and its VIO pin accepts 3.3V, 1.8V, 2.5V, or 5V to match the target logic directly without level shifters. In a typical adapter, the chip enumerates via the OS CDC driver or the WCH VCP driver, and the RTS/DTR MODEM signals drive the MCU auto-reset and boot-mode strapping circuits, enabling one-button flashing. Because the crystal is integrated, the adapter PCB needs only decoupling capacitors and the USB connector, keeping adapter cost near the chip price of roughly $0.74. Boards like the Waveshare CH343 USB UART Board demonstrate this exact topology.
推荐
Embedded Development Boards
Development and evaluation boards benefit from the CH343 as the on-board USB-to-serial bridge because it removes the external crystal (built-in oscillator saves layout area), supports dual power supply mode so the MCU can run from its own 3.3V, 2.5V, or 1.8V rail while VBUS powers the bridge, and offers hardware flow control for bootloaders or logs that need CTS/RTS. The 6 Mbps capability is valuable when streaming high-rate sensor logs or trace output that would saturate a 115200 bps legacy bridge. Per the WCH datasheet, only RXD and TXD are mandatory cross-connections in minimal designs, so a two-wire serial console costs almost nothing to add. Boards such as Waveshare modules use CH343 in exactly this role.
推荐
Industrial Equipment Serial Port Upgrade
Legacy industrial devices - PLC panels, meters, CNC accessories - often expose only RS-232/TTL serial ports, while service laptops ship without any COM ports. The CH343 bridges this gap: it enumerates as a standard CDC serial port on Windows, macOS, and Linux, so existing commissioning software runs unmodified, as noted in the WCH datasheet. Its -40C to +85C operating range covers industrial cabinet temperatures, and the automatic baud-rate adaptation (115200 bps and below) tolerates devices configured at non-standard legacy rates. In dual-supply mode the chip draws power from USB VBUS while the equipment-side logic stays on its own 5V or 3.3V rail, isolating grounds cleanly. The MODEM handshake signals support equipment requiring hardware flow control.
推荐
USB-to-UART Adapter Cables and Dongles
Consumer and maker USB-to-TTL dongles are the highest-volume application for the CH343 family. The chip's integrated crystal eliminates the single most failure-prone external passive of older CH340G designs, its 6 Mbps ceiling supports fast serial flashing tools, and CDC class-driver operation means end users plug the dongle into Windows 10/11, macOS, or Linux with zero driver installation. The VIO flexibility (5V/3.3V/2.5V/1.8V, selectable by tying the VIO pin) lets one dongle PCB serve multiple logic families by populating a jumper. At roughly $0.74 unit cost from LCSC as of 2026-10-20, total dongle BOM stays well under one dollar, undercutting CP2102- or FT232-based designs by several multiples while exceeding their speed.
推荐
Point-of-Sale and Instrumentation Links
POS terminals, barcode scanners, lab instruments, and medical accessories frequently communicate over asynchronous serial at moderate rates. The CH343 suits these products because the WCH vendor VCP driver exposes configurable latency and buffering for reliable transaction throughput, the built-in firmware emulates a standard UART so application software is untouched, and the CDC mode simplifies certification on modern OS versions. Per the datasheet, common MODEM signals support peripherals with hardware handshake requirements, and the 6 Mbps ceiling accommodates high-speed receipt or data-logging traffic. Dual-supply operation lets the peripheral run from its own isolated 3.3V or 5V rail while the host side is bus-powered - useful for meeting safety isolation practices in instrumentation enclosures.
推荐
IoT Gateways and Smart Home Hubs
IoT gateways often use a USB-connected serial console for module management, Zigbee/Thread co-processor flashing, or cellular modem AT-command channels. The CH343 fits these roles with its 6 Mbps throughput (sufficient for modem AT streams and co-processor image downloads), 1.8V VIO support matching modern low-voltage co-processors, and -40C to +85C rating for unconditioned enclosures. Because Linux enumerates the chip via the built-in CDC driver, no kernel module maintenance is needed across OS updates - a real operational benefit for fleet-deployed gateways. Waveshare's CH343 USB UART Board documentation shows CFG-pin configuration for CDC mode, which is the recommended setting for headless Linux hosts using software flow control by default.
推荐
推荐产品汇总
工程参考数据： CH343 ——对比、设计指导和合规信息。
选型指南
与替代料对比
| 参数 | 本产品 | CH343G | CH343P | CH343C | FT232RL |
|---|---|---|---|---|---|
| Package | SOP-16 (CH343G) | SOP-16 | SOP-16 | SOP-16 | SSOP-28 (not pin-compatible) |
| Brand | WCH | WCH | WCH | WCH | FTDI |
| Max Baud Rate | 6 Mbps | 6 Mbps | 6 Mbps | 6 Mbps | 3 Mbps |
| VIO Logic Levels | 5V / 3.3V / 2.5V / 1.8V | 5V / 3.3V / 2.5V / 1.8V | 5V / 3.3V / 2.5V / 1.8V | 5V / 3.3V / 2.5V / 1.8V | 5V / 3.3V only |
| Integrated Crystal | Yes | Yes | Yes | Yes | Yes |
| Typical Unit Price | $0.74 (LCSC, 2026-10-20) | $0.7342 (LCSC) | $0.90 - $1.20 (est.) | $0.80 - $1.00 (est.) | $3 - $5 (est.) |
| Operating Temperature | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C |
| Driver Support | CDC built-in + WCH VCP | CDC built-in + WCH VCP | CDC built-in + WCH VCP | CDC built-in + WCH VCP | FTDI VCP/D2XX (mature ecosystem) |
关键差异点
- Highest baud rate in cost class （对比 FT232RL)
- Ultra-low-voltage logic support （对比 CP2102)
- No external crystal required （对比 CH340G)
设计说明
In dual power supply mode, power the CH343 from USB VBUS and feed VIO from the target MCU's own self-powered rail (5V, 3.3V, 2.5V, or 1.8V per the WCH datasheet). Never let VIO float or exceed the MCU rail, or the RXD/TXD drivers can overdrive the target. Place 0.1uF decoupling on VCC and VIO close to the pins; excepting RXD and TXD, other signal pins are optional connections in minimal designs.
The CFG pin determines CDC vs VCP behavior: the Waveshare CH343 USB UART Board documentation notes that boards default to software flow control, and hardware flow control requires connecting CFG to EN for CDC mode, then enabling flow control in the host application for VCP mode. If your adapter appears to enumerate but data will not flow, check CFG first. Also confirm the suffix (G/K/P/C) pin map in CH343DS1 before layout, since assignments differ between package variants.
Because the crystal is built in, keep the USB D+/D- pair routed as a matched 90-ohm differential pair no longer than necessary, and reserve test points on TXD/RXD for bring-up. For auto-reset flashing circuits, route DTR/RTS through a pair of small-signal transistors (classic RTS/DTR cross-coupling) to the target EN/BOOT pins, matching ESP32 reference designs.
合规信息
RoHS compliance stated on LCSC product listing for CH343G; other compliance attributes not stated in provided data.
