db9-usb Future Technology Devices International Ltd., db9-usb Datasheet - Page 3

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

Document Reference No.: FT_000204
DB9-USB Datasheet
Version 2.1
Clearance No.: FTDI# 130
Figure 1.1 – DB9-USB Family
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 Voltage 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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