Future Technology Devices International Ltd
The DB9-USB Family of
UART Converter Modules
Datasheet
Document Reference No.: FT_000204
Version 2.0
Issue Date: 2011-08-31
Future Technology Devices International Ltd (FTDI)
Unit 1, 2 Seaward Place, Centurion Business Park, Glasgow, G41 1HH, United Kingdom
Tel.: +44 (0) 141 429 2777
Fax: + 44 (0) 141 429 2758
E-Mail (Support): support1@ftdichip.com Web: http://www.ftdichip.com
Use of FTDI devices in life support and/or safety applications is entirely at the user’s risk, and the user agrees to
defend, indemnify and hold harmless FTDI from any and all damages, claims, suits or expense resulting from such
use.
Copyright © 2011 Future Technology Devices International Limited
Document Reference No.: FT_000204
DB9-USB Datasheet
Version 2.0
Clearance No.: FTDI# 130
1
Introduction
1.1
The DB9-USB Family of UART Converter Modules
The DB9-USB connector modules can be used to upgrade an RS232 port to an active USB port without
the need to redesign the PCB.
The DB9-USB family consist of 6 modules. Two of these operate at RS232 voltage levels, while four of
them operate at digital voltage levels (a choice of 5V or 3.3V). Each is available to replace either a male
or a female DB9.
1.2
Functional Description
DB9-USB modules can be used to upgrade a UART port of a device to an active USB port without the
need for redesigning the device’s PCB. These active connectors contain all the USB to UART (and vice-
versa) conversion electronics and are designed to fit directly into the same PCB footprint as a PC
compatible UART DB9 connector.
The FTDI DB9-USB-RS232 modules are available in two types DB9-USB-RS232-M and DB9-USB-RS232-F.
A
DB9-USB-RS232-M
can be used to replace a male DB9 connector that is wired in a PC compatible
RS232 manner. This module operates at
RS232
signal levels.
A
DB9-USB-RS232-F
can be used to replace a female DB9 connector that is wired in a PC compatible
RS232 manner. This module operates at
RS232
signal levels.
The FTDI DB9-USB-D3 modules are available in two types DB9-USB-D3-M and DB9-USB-D3-F.
A
DB9-USB-D3-M
can be used to replace a male DB9 connector that is wired in a PC compatible RS232
manner. This module operates at
3.3V
signal levels.
A
DB9-USB-D3-F
can be used to replace a female DB9 connector that is wired in a PC compatible RS232
manner. This module operates at
3.3V
signal levels.
The FTDI DB9-USB-D5 modules are available in two types DB9-USB-D5-M and DB9-USB-D5-F.
A
DB9-USB-D5-M
can be used to replace a male DB9 connector that is wired in a PC compatible RS232
manner. This module operates at
5.0V
signal levels.
A
DB9-USB-D5-F
can be used to replace a female DB9 connector that is wired in a PC compatible RS232
manner. This module operates at
5.0V
signal levels.
The purposes of these modules is to provide a simple method of adapting legacy serial devices with UART
interfaces to modern USB ports by replacing the DB9 connector with this miniaturised module which
closely resembles a DB9 connector. This is accomplished by incorporating the industry standard FTDI
FT232R USB-Serial Bridge IC. The RS232 level DB9-USB modules include an RS232 level transceiver.
Figure 1.1 – DB9-USB Family
Copyright © 2011 Future Technology Devices International Limited
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Document Reference No.: FT_000204
DB9-USB Datasheet
Version 2.0
Clearance No.: FTDI# 130
DB9-USB modules use a standard USB-MINI-B connector for connection to an upstream host or hub port.
RS232 Level:
RS232 level signals, includes modem handshake signals, and capable of transmitting data
at rates up to 1 Mega Baud.
Digital Level:
3.3V or 5V level signals, includes modem handshake signals, and capable of transmitting
data at rates up to 3 Mega Baud.
DB9-USB modules require USB device drivers, available free from www.ftdichip.com, which are used to
make DB9-USB modules appear as a Virtual COM Port (VCP). This allows existing serial communications
software, such as HyperTerminal, to exchange data through the DB9-USB to a legacy UART peripheral
device.
1.3
Background
In the long distant past, there was no standard defined for the connections on a DB9 connector when it
was used as an RS232 interface. That changed when IBM introduced the PC-AT. This introduced a
generally accepted
DB9 RS232 standard and PC peripherals adopted the same pin-out using a 1-to-1
cable connection between the PC and the peripheral.
DB9-USB modules have adopted this standard. The DB9 connector wire schemes used by this module
either the standard male or standard female wire configuration.
Note that
NOT ALL
peripheral adopted this standard so it is important for the user to check against the
pin-out used for the male and female DB9-USB connectors.
Note: DB9 connectors are also known as DE9 connector since it consists of 9 pins in a size E
shell. However DE9 connectors are more commonly referred to as DB9 connector.
Copyright © 2011 Future Technology Devices International Limited
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Document Reference No.: FT_000204
DB9-USB Datasheet
Version 2.0
Clearance No.: FTDI# 130
1.4
Block Diagrams
DB9 Module
DB9 Module
USB Mini B
Client
Connector
FTDI FT232R
USB Serial Bridge
RS232
Level Shifter
DB9 PCB
Decal
Figure 1.2 – DB9-USB-RS232 Block Diagram
DB9 Module
DB9 Module
VIO
3.3V
VIO
3.3V
3V3OUT
3V3OUT
FTDI
FTDI
FT232R USB
FT232R USB
Serial Bridge
Serial Bridge
USB Mini B
Client
Connector
3.3V TTL/CMOS
3.3V TTL/CMOS
UART
UART
DB9 PCB
Decal
Figure 1.3 – DB9-USB-D3 Block Diagram
DB9 Module
DB9 Module
VIO
VIO
FTDI FT232R
USB Serial Bridge
5V TTL/CMOS
5V TTL/CMOS
UART
UART
5V
5V
USB Mini B
Client
Connector
DB9 PCB
Decal
Figure 1.4 – DB9-USB-D5 Block Diagram
1.4.1 Block description
USB Mini B Client Connector
This connector provides the interface for connection to a USB Host or Hub port.
FTDI FT232R
The FTDI FT232R provides the USB-to-Serial conversion. Operating system device drivers are required in
order to operate with the FT232R to provide the Virtual COM Port serial functionality.
RS232 Level Shifter
The RS232 level shifter converts the signals provided by the FT232R into the voltage levels required by
application RS232 interface.
DB9-USB PCB Footprint
The DB9-USB pin-out is configured to match the industry standard DB9 footprint. See section 3.
Copyright © 2011 Future Technology Devices International Limited
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Document Reference No.: FT_000204
DB9-USB Datasheet
Version 2.0
Clearance No.: FTDI# 130
1.5
Features
Adds one USB serial port by connecting to the RS232 DB9 footprint of a device
Easy placement for an standard Male and Female RS232 DB9 footprint of a device
A selection of RS232, 3.3V or 5V UART signal levels.
Works with USB 1.1 & 2.0 Host and Hub ports
Industry Standard FTDI chip set & device drivers for maximum compatibility
Microsoft Windows
®
WHQL-certified, Mac OS X, Linux and Windows CE device drivers
Installs as a standard Windows COM port
128 byte transmit buffer, 256 byte receive buffer
UART data signals: TxD, RxD, RTS, CTS, DSR, DTR, DCD, RI, GND
Powered by USB port. No external power adapter required.
Serial port speed up to 1Mbps (RS232 levels) or 3Mbps (3.3V/5V levels)
Serial Communication Parameters
o
o
o
Parity: None, Even, Odd
Data bits: 7, 8
Flow control: RTS/CTS , DSR/DTR, X-ON/X-OFF, None
Operating temperature of -40°C to +85°C
Copyright © 2011 Future Technology Devices International Limited
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