db9-usb Future Technology Devices International Ltd., db9-usb Datasheet - Page 2

• Manufacturer Part Number: db9-usb
• Description: The Db9-usb Family Of Usb To Uart Converter Modules
• Manufacturer: Future Technology Devices International Ltd.

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1.1
The DB9-USB connector modules can be used to upgrade an RS232 port to an active USB port. In some
cases this can be done without the need to redesign the PCB. In some cases they can reduce system
costs by removing an RS232 level shifter from a design.
The DB9-USB family consist of 6 modules. Two of these operate at RS232 voltage levels – these can be
used as a direct replacement in a system which uses RS232 levels, while four of them operate at digital
voltage levels (a choice of 5V or 3.3V) – these can be used to interface to an application systems logic
level which could result in the bill-of-materials being reduced by the removal of any RS232 level shifters
which may be in the system. Each is available to replace either a male or a female DB9.
1.2
DB9-USB modules can be used to upgrade a UART port of a device to an active USB port. 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 level modules are available in two types DB9-USB-M and DB9-USB-F. Using
these modules does not require any changes to a PCB or enclosure.
A DB9-USB-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-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 3.3V digital voltage level modules are available in two types DB9-USB-D3-M and DB9-
USB-D3-F. Using these modules may require a minor change to the PCB, but saves in material costs by
removing the need for an RS232 level shifter.
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 5V digital voltage level modules are available in two types DB9-USB-D5-M and DB9-
USB-D5-F. Using these modules may require a minor change to the PCB, but saves in material costs by
removing the need for an RS232 level shifter.
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.
Introduction
The DB9-USB Family of UART Converter Modules
Functional Description
Copyright © 2011 Future Technology Devices International Limited
Document Reference No.: FT_000204
Clearance No.: FTDI# 130
DB9-USB Datasheet
Version 2.1
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