CH340 – USB to Serial Chip (CH340G)

Part Number : CH340

Function : USB to serial chip

Package : SSOP-20 Type

Manufacturers : WCH ( )

This post explains for the semiconductor CH340.

Image :


Description :

CH340 is a USB bus convert chip and it can realize USB convert to serial interface, USB convert to IrDA infrared or USB convert to printer interface. In serial interface mode, CH340 supplies common MODEM liaison signal, used to enlarge asynchronous serial interface of computer or upgrade the common serial device to USBbus directly. More detail about USB convert to printer interface please referring to the second manual CH340DS2. In infrared mode, add infrared transceiver to CH340 can compose USB infrared adapter, realize SIR nfrared communication.


CH340 Pinout




1. Full speed USB device interface, conforms to USB Specification Version 2.0, only needs crystal and
capacitance external.

2. Emulate standard serial interface, used to upgrade the former peripheral device, or add excess serial
interface through USB.

3. Totally compatible with serial application program in computer endpoint Windows operation system.

4. Hardware full duplex serial interface, set transceiver buffer, supports communication baud rate varies
from 50bps to 2Mbps.

5. Supports common MODEM liaison signal RTS, DTR, DCD, RI, DSR and CTS.

6. Through adding level converter equipment to supply RS232, RS485, RS422 and other interface.

7. Supports IrDA criterion SIR infrared communication, supports baud rate varies from 2400bps to

8. For it is through USB converts to serial interface, only compatible with application layer not totally.

9. Software compatible with CH341, using drive of CH341 directly.

10. Support 5V and 3.3V source voltage.


Block Diagram



Reference Site :

Other data sheets within the file : CH340G, CH340R, CH340T

CH340 Datasheet

CH340 pdf



25Q64FV Datasheet – 64M-bit, Serial Flash Memory – Winbond

This is one of the memory ic types.

Part Number : 25Q64FV, W25Q64FV


Package : SOP 8 Pin Type

Manufactures : Winbond Electronics

See the preview image and the PDF file for more information.


25Q64FV serial flash memory

The 25Q64FV (64M-bit) Serial Flash memory provides a storage solution for systems with limited space, pins and power. The 25Q series offers flexibility and performance well beyond ordinary Serial Flash devices. They are ideal for code shadowing to RAM, executing code directly from Dual/Quad SPI (XIP) and storing voice, text and data. The device operates on a single 2.7V to 3.6V power supply with current consumption as low as 4mA active and 1µA for power-down. All devices are offered in space saving packages.

The 25Q64FV array is organized into 32,768 programmable pages of 256-bytes each. Up to 256 bytes can be programmed at a time. Pages can be erased in groups of 16 (4KB sector erase), groups of 128 (32KB block erase), groups of 256 (64KB block erase) or the entire chip (chip erase). The W25Q64FV has 2,048 erasable sectors and 128 erasable blocks respectively. The small 4KB sectors allow for greater flexibility in applications that require data and parameter storage.


25Q64FV Pinout

25Q64FV datasheet pdf pinout

Space Efficient Packaging

1. 8-pin SOIC/VSOP 208-mil
2. 8-pad WSON 6×5-mm/8×6-mm
3. 16-pin SOIC 300-mil
4. 8-pin PDIP 300-mil
5. 24-ball TFBGA 8×6-mm
6. Contact Winbond for KGD and other options


25Q64FV Datasheet