Datasheet

Copyright © 2011 Future Technology Devices International Limited 11
Document Reference No.: FT_000204
DB9-USB Datasheet
Version 2.1
Clearance No.: FTDI# 130
3.1.1 Male DB9 UART Connector Signals
The DB9-USB-X-M can be used to replace a male DB9 connector used for transmitting UART signals.
Table 2.1 gives the pin out description of each pin/pad of a UART connector/footprint.
Pin
Number
Pin Type of DB9-
USB module
Pad Type at
application PCB
Description
1
Input
1
Input
1
DCD = Data Carrier Detect
2
Output
Input
RXD = Receive Data
(this is an output from the DB9-USB-X-M
to the application Rx input)
3
Input
Output
TXD = Transmit Data
(this is an input to the DB9-USB-X-M from
the application Tx output)
4
Input
Output
DTR = Data Terminal Ready
(this is an input to the DB9-USB-X-M from
the application DTR output)
5
Ground
Ground
GND = RS232 signal ground
6
Output
Input
DSR = Data Set Ready
(this is an output from the DB9-USB-X-M
to the application DSR input)
7
Input
Output
RTS = Request To Send
(this is an input to the DB9-USB-X-M from
the application RTS output)
8
Output
Input
CTS = Clear To Send
(this is an output from the DB9-USB-X-M
to the application CTS input)
9
Input
1
Input
1
RI = Ring Indicator
Shield
Ground
Case Ground
Drain = typically connected to the host PC
case
Table 2.1 – Male DB9 UART Signal Description
Note 1: These signals are irrelevant for DTE to DTE connections.