FT232R USB UART I.C. Datasheet Version 1.04

© Future Technology Devices International Ltd. 2005

Page 4

Lower Supply Voltage - Previous generations of the chip required 5V supply on the VCC pin. The FT232R will work

with a Vcc supply in the range 3.3V - 5.25V. Bus powered designs would still take their supply from the 5V on the USB

bus, but for self powered designs where only 3.3V is available and there is no 5V supply there is no longer any need

for an additional external regulator.

Integrated Level Converter on UART Interface and Control Signals - VCCIO pin supply can be from 1.8V to 5V.

Connecting the VCCIO pin to 1.8V, 2.8V, or 3.3V allows the device to directly interface to 1.8V, 2.8V or 3.3V and other

logic families without the need for external level converter I.C. devices.

5V / 3.3V / 2.8V / 1.8V Logic Interface - The FT232R provides true CMOS Drive Outputs and TTL level Inputs.

Integrated Power-On-Reset (POR) Circuit- The device incorporates an internal POR function. A RESET# pin is

available in order to allow external logic to reset the FT232R where required. However, for many applications the

RESET# pin can be left unconnected, or pulled up to VCCIO.

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 70μA. This allows greater margin for peripheral designs to meet

the USB suspend current limit of 500μA.

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.

High Output Drive Option - The UART interface and CBUS I/O pins can be made to drive out at three times the

standard signal drive level thus allowing multiple devices to be driven, or devices that require a greater signal drive

strength to be interfaced to the FT232R. This option is enabled in the internal EEPROM.

Power Management Control for USB Bus Powered, High Current Designs- The PWREN# signal can be used to

directly drive a transistor or P-Channel MOSFET in applications where power switching of external circuitry is required.

An option in the internal EEPROM makes the device gently pull down on its UART interface lines when the power

is shut off (PWREN# is high). In this mode any residual voltage on external circuitry is bled to GND when power is

removed, thus ensuring that external circuitry controlled by PWREN# resets reliably when power is restored.

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#.

FTDIChip-ID™ - Each FT232R is assigned a unique number which is burnt into the device at manufacture. This ID

number cannot be reprogrammed by product manufacturers or end-users. This allows the possibility of using FT232R

based dongles for software licensing. Further to this, a renewable license scheme can be implemented based on the

FTDIChip-ID™ number when encrypted with other information. This encrypted number can be stored in the user area

of the FT232R internal EEPROM, and can be decrypted, then compared with the protected FTDIChip-ID™ to verify

that a license is valid. Web based applications can be used to maintain product licensing this way. An application note

describing this feature is available separately from the FTDI website.

Improved EMI Performance - The reduced operating current and improved on-chip VCC decoupling significantly

improves the ease of PCB design requirements in order to meet FCC, CE and other EMI related specifications.

Programmable Receive Buffer Timeout - The receive buffer timeout is used to flush remaining data from the

receive buffer. This time defaults to 16ms, but is programmable over USB in 1ms increments from 1ms to 255ms, thus

allowing the device to be optimised for protocols that require fast response times from short data packets.

Extended Operating Temperature Range - The FT232R operates over an extended temperature range of -40º to

+85º C thus allowing the device to be used in automotive and industrial applications.

New Package Options - The FT232R is available in two packages - a compact 28 pin SSOP ( FT232RL) and an

ultra-compact 5mm x 5mm pinless QFN-32 package (

FT232RQ). Both packages are lead ( Pb ) free, and use a

‘green’ compound. Both packages are fully compliant with European Union directive 2002/95/EC.