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4.4 QFN-32 Package Signal Descriptions
Table 2 - QFN Package Pin Out Description
Pin No. Name
Type Description
USB Interface Group
14
15
USBDP
USBDM
I/O
I/O
USB Data Signal Plus, incorporating internal series resistor and 1.5kΩ pull up resistor to 3.3V
USB Data Signal Minus, incorporating internal series resistor.
Power and Ground Group
1
VCCIO
PWR
+1.8V to +5.25V supply to UART Interface and CBUS group pins (2,3, 6, ...,11, 21, 22, 30,..32). In USB bus
powered designs connect to 3V3OUT to drive out at 3.3V levels, or connect to VCC to drive out at 5V CMOS
level. This pin can also be supplied with an external 1.8V - 2.8V supply in order to drive out at lower levels. It
should be noted that in this case this supply should originate from the same source as the supply to Vcc. This
means that in bus powered designs a regulator which is supplied by the 5V on the USB bus should be used.
4, 17, 20
16
GND
PWR
Device ground supply pins
3V3OUT
Output 3.3V output from integrated L.D.O. regulator. This pin should be decoupled to ground using a 100nF capacitor.
The prime purpose of this pin is to provide the internal 3.3V supply to the USB transceiver cell and the internal
1.5kΩ pull up resistor on USBDP. Up to 50mA can be drawn from this pin to power external logic if required.
This pin can also be used to supply the FT232R’s VCCIO pin.
19
24
VCC
PWR
PWR
3.3V to 5.25V supply to the device core.
AGND
Device analog ground supply for internal clock multiplier
Miscellaneous Signal Group
5, 12, 13, NC
23, 25, 29
NC
No internal connection.
18
RESET#
Input
Can be used by an external device to reset the FT232R. If not required can be left unconnected or pulled up
to VCCIO.
26
27
28
TEST
OSCI
OSCO
Input
Input
Puts the device into I.C. test mode. Must be tied to GND for normal operation.
Input to 12MHz Oscillator Cell. Optional - Can be left unconnected for normal operation. *
Output Output from 12MHz Oscillator Cell. Optional - Can be left unconnected for normal operation if internal oscilla-
tor is used. *
UART Interface and CBUS Group **
30
31
32
2
TXD
DTR#
RTS#
RXD
RI#
Output Transmit Asynchronous Data Output.
Output Data Terminal Ready Control Output / Handshake signal.
Output Request To Send Control Output / Handshake signal.
Input
Input
Receive Asynchronous Data Input.
3
Ring Indicator Control Input. When remote wake up is enabled in the internal EEPROM taking RI# low can be
used to resume the PC USB host controller from suspend.
6
7
8
9
DSR#
DCD#
CTS#
Input
Input
Input
I/O
Data Set Ready Control Input / Handshake signal.
Data Carrier Detect Control input.
Clear to Send Control input / Handshake signal.
CBUS4
Configurable CBUS I/O Pin. Function of this pin is configured in the device internal EEPROM. Factory Default
function is SLEEP#. See CBUS Signal Options, Table 3.
10
11
21
22
CBUS2
CBUS3
CBUS1
CBUS0
I/O
I/O
I/O
I/O
Configurable CBUS I/O Pin. Function of this pin is configured in the device internal EEPROM. Factory Default
function is TXDEN. See CBUS Signal Options, Table 3.
Configurable CBUS I/O Pin. Function of this pin is configured in the device internal EEPROM. Factory Default
function is PWREN#. See CBUS Signal Options, Table 3.
Configurable CBUS I/O Pin. Function of this pin is configured in the device internal EEPROM. Factory Default
function is RXLED#. See CBUS Signal Options, Table 3.
Configurable CBUS I/O Pin. Function of this pin is configured in the device internal EEPROM. Factory Default
function is TXLED#. See CBUS Signal Options, Table 3.
* Contact FTDI technical support for details on how to use an external crystal, ceramic resonator, or oscillator with the
FT232R.
** When used in Input Mode, these pins are pulled to VCCIO via internal 200kΩ resistors. These pins can be
programmed to gently pull low during USB suspend ( PWREN# = “1” ) by setting an option in the internal EEPROM.
FT232R USB UART I.C. Datasheet Version 1.04
© Future Technology Devices International Ltd. 2005
FTDI [ FUTURE TECHNOLOGY DEVICES INTERNATIONAL LTD. ]
