[{"data":1,"prerenderedAt":285},["ShallowReactive",2],{"component:ch340g:en":3},{"component":4,"localizationFallbackIssues":231,"related":232,"equivalentSlugs":284},{"schemaVersion":5,"governance":6,"id":18,"mpn":19,"slug":18,"primaryCategory":20,"manufacturers":21,"lifecycleStatus":23,"shortDescription":24,"deepTechnicalOverview":25,"packages":26,"absoluteMaximums":108,"recommendedOperating":113,"parametricAttributes":116,"gotchas":176,"datasheetUrl":17,"documentationSources":196,"applicationCircuits":204,"equivalents":205,"mountedOnBoards":216,"seo":222},"1.0.0",{"publication":7,"verification":10,"provenance":15},{"status":8,"publishedDate":9},"published","2026-10-11",{"status":11,"verifiedDate":9,"verifiedBy":12,"checklist":13},"verified","Serhii Shvab (owner sign-off of review pack batch 2, prepared by Claude against the cited datasheets)",{"schema":14,"technicalFacts":14,"relationships":14,"sources":14},true,{"sourceUrls":16},[17],"https:\u002F\u002Fwww.wch-ic.com\u002Fdownloads\u002FCH340DS1_PDF.html","ch340g","CH340G","interface_bridge",[22],"WCH (Jiangsu Qinheng)","active","USB to UART serial bridge in SOP-16 with modem signals and an external 12 MHz crystal, common on low-cost Arduino-compatible and ESP8266 boards.","The CH340G is a full-speed USB 2.0 to serial bridge from WCH. It provides TXD\u002FRXD plus the modem signals RTS#, DTR#, CTS#, DSR#, RI# and DCD#, supports baud rates from 50 bps to 2 Mbps and runs from either 5 V or 3.3 V. Unlike the CH340C\u002FN\u002FK\u002FE\u002FX\u002FB, it needs an external 12 MHz crystal. On a computer it uses WCH's CH341 VCP driver. Board makers usually drive an auto-reset circuit from DTR# and RTS#. The figures on this page come from the WCH CH340 datasheet, version 3D.",[27],{"packageType":28,"pinCount":29,"bodyDimensionsMm":30,"pitchMm":34,"pins":35},"SOP-16",16,{"length":31,"width":32,"height":33},9.9,3.9,1.75,1.27,[36,42,48,53,58,62,66,71,76,80,84,88,92,96,100,105],{"pinNumber":37,"pinName":38,"electricalType":39,"isFiveVoltTolerant":14,"internalPull":40,"description":41},1,"GND","ground","none","Common ground, connected directly to the USB ground",{"pinNumber":43,"pinName":44,"electricalType":45,"isFiveVoltTolerant":46,"internalPull":40,"description":47},2,"TXD","digital_io",false,"Serial data output (transmit); idle high",{"pinNumber":49,"pinName":50,"electricalType":45,"isFiveVoltTolerant":46,"internalPull":51,"description":52},3,"RXD","programmable","Serial data input (receive) with built-in controllable pull-up and pull-down; idle high",{"pinNumber":54,"pinName":55,"electricalType":56,"isFiveVoltTolerant":14,"internalPull":40,"description":57},4,"V3","power_in","Internal 3.3 V node: 0.1 µF to GND when VCC is 5 V; tie to VCC when VCC is 3.3 V",{"pinNumber":59,"pinName":60,"electricalType":45,"isFiveVoltTolerant":46,"internalPull":40,"description":61},5,"UD+","USB D+; connect directly to the USB bus without a series resistor (pull-up is internal)",{"pinNumber":63,"pinName":64,"electricalType":45,"isFiveVoltTolerant":46,"internalPull":40,"description":65},6,"UD-","USB D−; connect directly to the USB bus without a series resistor",{"pinNumber":67,"pinName":68,"electricalType":69,"isFiveVoltTolerant":46,"internalPull":40,"description":70},7,"XI","analog_in","Crystal oscillator input: 12 MHz crystal with load capacitor to GND",{"pinNumber":72,"pinName":73,"electricalType":74,"isFiveVoltTolerant":46,"internalPull":40,"description":75},8,"XO","analog_out","Crystal oscillator output: 12 MHz crystal with load capacitor to GND",{"pinNumber":77,"pinName":78,"electricalType":45,"isFiveVoltTolerant":46,"internalPull":40,"description":79},9,"CTS#","Clear To Send modem input, active low (internal pull-up not stated in the datasheet)",{"pinNumber":81,"pinName":82,"electricalType":45,"isFiveVoltTolerant":46,"internalPull":40,"description":83},10,"DSR#","Data Set Ready modem input, active low (internal pull-up not stated in the datasheet)",{"pinNumber":85,"pinName":86,"electricalType":45,"isFiveVoltTolerant":46,"internalPull":40,"description":87},11,"RI#","Ring Indicator modem input, active low (internal pull-up not stated in the datasheet)",{"pinNumber":89,"pinName":90,"electricalType":45,"isFiveVoltTolerant":46,"internalPull":40,"description":91},12,"DCD#","Data Carrier Detect modem input, active low (internal pull-up not stated in the datasheet)",{"pinNumber":93,"pinName":94,"electricalType":45,"isFiveVoltTolerant":46,"internalPull":40,"description":95},13,"DTR#","Data Terminal Ready modem output, active low; often drives the MCU auto-reset. Before USB configuration it is read as an input (4.7 kΩ pull-down requests a larger supply current)",{"pinNumber":97,"pinName":98,"electricalType":45,"isFiveVoltTolerant":46,"internalPull":40,"description":99},14,"RTS#","Request To Send modem output, active low; often drives the boot\u002Freset circuit",{"pinNumber":101,"pinName":102,"electricalType":45,"isFiveVoltTolerant":46,"internalPull":103,"description":104},15,"R232","pulldown","Auxiliary RS232 enable, active high, built-in pull-down; leave unconnected for a TTL UART",{"pinNumber":29,"pinName":106,"electricalType":56,"isFiveVoltTolerant":14,"internalPull":40,"description":107},"VCC","Supply: 4.0–5.3 V (5 V mode) or 2.9–3.6 V with V3 tied to VCC; 0.1 µF decoupling capacitor",{"supplyVoltageMaxV":63,"operatingTempMinC":109,"operatingTempMaxC":110,"storageTempMinC":111,"storageTempMaxC":112},-40,85,-55,125,{"supplyVoltageMinV":114,"supplyVoltageTypV":59,"supplyVoltageMaxV":115},2.9,5.3,[117,122,128,135,141,147,153,159,163,170],{"symbol":118,"name":119,"typicalValue":59,"minValue":54,"maxValue":115,"unit":120,"testCondition":121},"VCC_5V","Supply Voltage, 5 V Mode","V","V3 connected only to a 0.1 µF capacitor",{"symbol":123,"name":124,"typicalValue":125,"minValue":114,"maxValue":126,"unit":120,"testCondition":127},"VCC_3V3","Supply Voltage, 3.3 V Mode",3.3,3.6,"V3 tied to VCC (CH340G)",{"symbol":129,"name":130,"typicalValue":131,"minValue":132,"maxValue":133,"unit":120,"testCondition":134},"VIO","Pin Voltage","—",-0.5,"VCC + 0.5","Absolute maximum; I\u002FO is not 5 V tolerant at 3.3 V",{"symbol":136,"name":137,"typicalValue":67,"maxValue":138,"unit":139,"testCondition":140},"ICC","Supply Current",20,"mA","VCC = 5 V, operating (4 \u002F 12 mA at 3.3 V)",{"symbol":142,"name":143,"typicalValue":144,"maxValue":145,"unit":139,"testCondition":146},"ISLP","Suspend Current",0.09,0.2,"USB suspended, VCC = 5 V",{"symbol":148,"name":149,"typicalValue":150,"unit":151,"testCondition":152},"Baud","Baud Rate","50 bps – 2 Mbps","bps","Standard rates up to 2 000 000",{"symbol":154,"name":155,"typicalValue":156,"unit":157,"testCondition":158},"BaudErr","Transmit Baud Rate Error","\u003C 0.3","%","CH340G with a 12 MHz crystal; receive tolerance about 2 %",{"symbol":160,"name":161,"typicalValue":162,"unit":160},"USB","USB Interface","2.0 Full-Speed",{"symbol":164,"name":165,"typicalValue":89,"minValue":166,"maxValue":167,"unit":168,"testCondition":169},"f_osc","Crystal Frequency",11.98,12.02,"MHz","33 pF load capacitors (47 pF for a ceramic resonator)",{"symbol":171,"name":172,"typicalValue":173,"minValue":174,"maxValue":175,"unit":120},"VR","Power-On Reset Threshold",2.6,2.4,2.8,[177,182,187,191],{"title":178,"severity":179,"description":180,"mitigationStrategy":181},"Wire V3 for Your Supply Voltage","critical","Pin 4 (V3) is wired differently in the two supply modes. At 5 V, V3 gets only a 0.1 µF capacitor to GND and must not be connected to VCC. At 3.3 V, V3 is tied to VCC, and nothing connected to the chip may exceed 3.3 V.","5 V: 0.1 µF from V3 to GND. 3.3 V: connect V3 to VCC and keep every connected signal at 3.3 V.",{"title":183,"severity":184,"description":185,"mitigationStrategy":186},"No Series Resistors on D+ and D−","warning","The USB transceiver and the D+ pull-up are internal. WCH recommends connecting UD+ and UD− straight to the USB lines without extra resistors.","Route UD+\u002FUD− directly to the connector as a parallel pair with ground on both sides.",{"title":188,"severity":184,"description":189,"mitigationStrategy":190},"Back-Powering Between Separately Powered Chips","If the CH340G runs from USB VBUS while the MCU has its own supply, current flows through TXD\u002FRXD into whichever side is unpowered. The CH340G pins are not protected against this (unlike CH340K, CH340X and later CH340C\u002FN lots).","Power both from the same supply, or add the diode and N-MOSFET isolation from section 7.7 of the datasheet.",{"title":192,"severity":193,"description":194,"mitigationStrategy":195},"Crystal Load Capacitors","info","The CH340G needs a 12 MHz quartz crystal between XI and XO with 33 pF capacitors to GND; a ceramic resonator usually needs about 47 pF. If the oscillator is hard to start, WCH suggests halving the XI capacitor.","Keep XI\u002FXO traces short and the crystal close to the chip, surrounded by ground.",[197],{"title":198,"url":17,"type":199,"authority":200,"publisher":22,"documentNumber":201,"revision":202,"language":203},"CH340 USB to Serial Port Chip Datasheet","datasheet","primary","CH340DS1","3D","EN",[],[206,211],{"equivalentMpn":207,"manufacturer":208,"compatibilityType":209,"parameterDifferences":210},"CH340C","WCH","pin_to_pin_drop_in","Built-in clock: omit the crystal and its capacitors; pin 7 must be left unconnected and pin 8 becomes OUT#. Operating range −20…70 °C; transmit baud error below 1.8 %.",{"equivalentMpn":212,"manufacturer":213,"compatibilityType":214,"parameterDifferences":215},"CP2102","Silicon Labs","functional_requires_bom_change","Different package (QFN-28) and pinout, with its own driver; see the Silicon Labs datasheet.",[217],{"boardSlug":218,"boardName":219,"designator":220,"roleOnBoard":221},"wemos-d1-mini-v3","WeMos D1 Mini","U3","USB Programming & Telemetry",{"canonicalUrl":223,"metaTitle":224,"metaDescription":225,"primarySearchCluster":226,"structuredDataSchema":230},"https:\u002F\u002Fcircuitbase.tech\u002Fcomponent\u002Fch340g","CH340G USB to UART Converter Pinout & Circuit | CircuitBase","CH340G pinout (SOP-16), V3 wiring for 5 V and 3.3 V, 12 MHz crystal, supply limits and USB wiring rules, from the WCH datasheet.",[227,228,229],"ch340g pinout","ch340g datasheet","ch340g schematic circuit","Product",null,[233,249,267],{"id":234,"slug":234,"mpn":235,"primaryCategory":236,"manufacturers":237,"shortDescription":240,"packages":241,"packageTypes":244,"voltage":245,"recommendedOperating":248},"ams1117-3-3","AMS1117-3.3","voltage_regulator",[238,239],"Advanced Monolithic Systems","Various","1A low-dropout positive linear voltage regulator with fixed 3.3V output in SOT-223 package.",[242],{"packageType":243,"pinCount":54},"SOT-223",[243],{"context":246,"min":247,"max":101,"typical":59,"outputTypical":125},"input",4.75,{"supplyVoltageMinV":247,"supplyVoltageTypV":59,"supplyVoltageMaxV":101},{"id":250,"slug":250,"mpn":251,"primaryCategory":236,"manufacturers":252,"shortDescription":256,"packages":257,"packageTypes":262,"voltage":263,"recommendedOperating":266},"lm7805","LM7805",[253,254,255],"Texas Instruments","STMicroelectronics","onsemi","5 V, 1.5 A fixed positive linear voltage regulator with internal current limiting and thermal shutdown, in TO-220 and D2PAK packages.",[258,260],{"packageType":259,"pinCount":49},"TO-220",{"packageType":261,"pinCount":49},"D2PAK",[259,261],{"context":246,"min":264,"max":265,"typical":81,"outputTypical":59},7.5,25,{"supplyVoltageMinV":264,"supplyVoltageTypV":81,"supplyVoltageMaxV":265},{"id":268,"slug":268,"mpn":269,"primaryCategory":270,"manufacturers":271,"shortDescription":273,"packages":274,"packageTypes":279,"voltage":280,"recommendedOperating":283},"ne555","NE555P","timer_driver",[253,254,255,272],"Diodes Incorporated","Industry-standard precision bipolar timer IC for astable multivibrators, monostable pulse generation, and PWM controllers.",[275,277],{"packageType":276,"pinCount":72},"DIP-8",{"packageType":278,"pinCount":72},"SOIC-8",[276,278],{"context":281,"min":282,"max":29,"typical":59},"supply",4.5,{"supplyVoltageMinV":282,"supplyVoltageTypV":59,"supplyVoltageMaxV":29},{},1791754292066]