Electronic Components Datasheet Search
  English  ▼

Delete All
ON OFF


CH341A Datasheet(PDF) 6 Page - List of Unclassifed Manufacturers

Part No. CH341A
Description  CH341 is a USB bus convert chip, providing UART, printer port, parallel and synchronous serial with 2-wire or 4-wire through USB bus
Download  14 Pages
Scroll/Zoom Zoom In 100% Zoom Out
Maker  ETC2 [List of Unclassifed Manufacturers]
Homepage  
Logo 

 6 page
background image
The DataSheet of CH341 (the first)
6
Output
18
13
DCK
Tri-state
Output
4-wire/5-wire serial interface clock output, other name is
SCK
17~15 12~10
CS2~CS0
Tri-state
Output
4-wire serial interface chip select output 2#~0#
24
No
SCL
Drain open
Output
2-wire serial interface clock output, with pull-up resistor
23
No
SDA
Drain open
OUT/IN
2-wire serial interface data input/output, with pull-up
resistor
26
19
RST#
OUT
Reset output, low-level active
7
3
INT#
IN
Interrupt request input, active with rising edge, with
pull-up resistor
5,8,6
No
IN
Self-define common input, with pull-up resistor
5. Function explanation
5.1.General explanation
The data in this manual has three types. Binary numbers are followed by a “B”. Hexadecimal numbers
are followed by an “H”. Numbers without annotations are decimals.
CH341 is a convert chip of USB bus, providing asynchronous serial interface, standard USB printer
port, parallel interface and synchronous serial interface. The manual mainly supplies asynchronous serial
interface and printer port explanation. The introduction of parallel interface and asynchronous serial
interface can refer to the second manual.
5.2.Hardware introduction
Some pins of the CH341 have many functions, so they have different features during reset period and
working normally after reset. All the pins with tri-state output have set pull-up resistors internal. They are
output pins after chip reset and during the reset time they are forbidden with tri-state output, pull-up resistors
supply pull-up current. If necessary, set pull-up resistors or pull-down resistors outside to set default level in
relevant pins during reset time. The external resistors are 2KΩ~5KΩ. For example, the tri-state is forbidden
of AS# during reset time in parallel interface mode, only depends on pull-up current to retain high-level. In
order to avoid disturbing peripheral circuit, a 3KΩ pull-up resistor can add to keep steady high-level.
The ACT# of CH341 is output state of USB device configuration completion. The pin output high-level
when USB device is un-configuration or configuration is cancelled. After USB configuration, the pin output
low-level. The ACT# pin of CH341 can attach to current-limited resistance LED to indicate relative state of
USB device configuration.
CH341 sets USB pull-up resistance internal, UD+ and UD- pin must connect to USB bus directly.
CH341 set power-up reset circuit internal. RSTI is used to input asynchronous reset signal from outside.
The CH341 is reset when RETI is high-level; the CH341 will delay about 20mS to reset then step into work
normally when the RSTI recover to low-level. In order to reset credibly during power up and decrease
disturb from outside, recommend to over connect a 0.47uF capacitance between RSTI and VCC.
Supplies 12MHz clock signal for XI pin to ensure CH341 work normally. In common, the clock signal
is generated by inverter in CH341 through oscillating of crystal keeping frequency. A crystal of 12MHz
between XI and XO can compose the peripheral circuit and connects an oscillator capacitance to ground
respectively.




Html Pages

1  2  3  4  5  6  7  8  9  10  11  12  13  14 


Datasheet Download




Link URL

Does ALLDATASHEET help your business so far?  [ DONATE ]  

About Alldatasheet   |   Advertisement   |   Contact us   |   Privacy Policy   |   Bookmark   |   Link Exchange   |   Manufacturer List
All Rights Reserved© Alldatasheet.com


Mirror Sites
English : Alldatasheet.com  , Alldatasheet.net  |   Chinese : Alldatasheetcn.com  |   German : Alldatasheetde.com  |   Japanese : Alldatasheet.jp  |   Russian : Alldatasheetru.com
Korean : Alldatasheet.co.kr   |   Spanish : Alldatasheet.es  |   French : Alldatasheet.fr  |   Italian : Alldatasheetit.com  |   Portuguese : Alldatasheetpt.com  |   Polish : Alldatasheet.pl