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Contents

README

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CH340B

WCH Jiangsu Qin Heng · USB Converters · SOP-16

CH340B from WCH Jiangsu Qin Heng, in a SOP-16. Pinout and pin descriptions extracted from the manufacturer datasheet by ds2sf; symbol, footprint, and 3D from KiCad-official CAD.

Pinout

Pin Name Type Function
1 GND power_in Common ground, directly connected to USB bus ground line.
2 TXD output Serial data output with idle state high level for CH340C/N/E/X/B/T.
3 RXD input Serial data input with built-in controllable pull-up and pull-down resistors.
4 V3 power_in 3.3V power supply connection for external power input (3.3V mode) or 0.1µF power decoupling capacitor (5V mode).
5 UD+ bidirectional Direct connection to USB bus D+ data line, do not add series resistor.
6 UD- bidirectional Direct connection to USB bus D- data line, do not add series resistor.
7 RST# input External reset input, active low with internal pull-up resistor (CH340B only).
8 NC unconnected No connection, empty pin must be left floating (CH340B only).
9 CTS# input MODEM contact input signal for clear to send, active low or high per software definition.
10 DSR# input MODEM contact input signal for data set ready, active low or high per software definition.
11 RI# input MODEM contact input signal for ring indicator, active low or high per software definition.
12 DCD# input MODEM contact input signal for carrier detect, active low or high per software definition.
13 DTR# output MODEM contact output signal for data terminal ready, active low or high per software definition.
14 RTS# output MODEM contact output signal for request to send, active low or high per software definition.
15 TNOW output Serial port transmission in progress status indicator, active high level (CH340T/E/X/B).
16 VCC power_in Positive power supply input, requires external 0.1µF power decoupling capacitor.

Key specifications

Parameter Value
Manufacturer WCH Jiangsu Qin Heng
Package SOP-16
Category Interface
Pins 16

CAD (KiCad official)

  • Symbol: CH340B
  • Footprint: Package_SO:SOIC-16_3.9x9.9mm_P1.27mm
  • 3D model: SOP-16 (KiCad packages3D, STEP)
  • 3D model files: ch340b-etched.step / ch340b-etched.glb carry the MPN laser-etched on the die in a toggleable Adom.LaserEtch group (Fusion-ready); ch340b.step / ch340b.glb are the bare package body.

Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

  • Datasheet: WCH Jiangsu Qin Heng datasheet (10 pp, sha256 6a6922d3c4de2d4f, retrieved 2026-09-17, tier: lcsc)
  • Datasheet language: Chinese. Pin names, descriptions, and specs on this page were extracted and translated to English by ds2sf; the linked PDF is the manufacturer original.
  • Extractor: parts-factory 2.0.0 / extract_pins 0.2, primary claude-haiku-4-5-20251001 (text), consensus claude-sonnet-4-6 (agreed), guards: pin_guards 0.1: passed. Pins are checked against the footprint pad set and their cited datasheet pages before publish.
  • CAD: KiCad official libraries (CC-BY-SA 4.0).

Datasheet PDF