Document Reference No.: FT_000151
DS_US232R-10(R-100) USB TO RS232 ADAPTER CABLE Data Sheet
Version 1.0
Clearance No.: #99
2 FT232R Key features
This section summarises the key features and enhancements of the FT232R IC device which
is used on the US232R USB to RS232 converter cable. For further details, consult the
FT232R datasheet, which is available from the FTDI website.
2.1.1 Integrated EEPROM
Previous generations of FTDI’s USB UART devices required an external EEPROM if the
device were to use USB Vendor ID (VID), Product ID (PID), serial number and product
description strings other than the default values in the device itself. This external EEPROM
has now been integrated onto the FT232R chip meaning that all designs have the option to
change the product description strings. A user area of the internal EEPROM is available for
storing additional data. The internal EEPROM is programmable in circuit, over USB without
any additional voltage requirement.
2.1.2 Pre-programmed EEPROM
The FT232R is supplied with its internal EEPROM preꢀprogrammed with a serial number
which is unique to each individual device. This, in most cases, will remove the need to
program the device EEPROM.
2.1.3 Lower Operating and Suspend Current
The device operating supply current has been further reduced to 15mA,
and the suspend current has been reduced to around 70ꢁA. This allows greater margin for
peripheral designs to meet the USB suspend current limit of 500ꢁA.
2.1.4 Low USB Bandwidth Consumption
The operation of the USB interface to the FT232R has been designed to use as little as
possible of the total USB bandwidth available from the USB host controller.
2.1.5 UART Pin Signal Inversion
The sense of each of the eight UART signals can be individually inverted by setting
options in the internal EEPROM. Thus, CTS# (active low) can be changed to CTS (active
high), or TXD can be changed to TXD#.
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