3.2 Signal Descriptions
Table 1 - Module Pin Out Description
Pin No. Name
1
2
SHEILD
VCC
Page
Type
GND
PWR
or Input
Description
USB Cable shield.
To power the module from the 5V supply on USB bus connect pins 15 (USBPWR) and 14 (VCC50) together.
In this case this pin becomes a 5V output, and can be used to supply the VCCIO pin, or to supply external
logic.
To use the MM232R module in a self powered configuration supply an external 3V - 5V supply to this pin, and
do not connect together pins 15 and 14.
+1.8V to +5.25V supply to the FT232RQ’s UART Interface and CBUS I/O pins. In USB bus powered designs
connect to 3V3 to drive out at 3.3V levels (connect VCCIO to VCC3O), or connect to VCC to drive out at 5V
CMOS level (connect VCCIO to VCC). This pin can also be supplied with an external 1.8V - 2.8V supply in or-
der 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.
3
VCCIO
4
VCC3O
Output
3.3V output from integrated L.D.O. regulator. This pin is decoupled to ground on the module pcb with 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 FT232RQ’s VCCIO pin by connecting this pin to pin 3
(VCCIO).
Transmit Asynchronous Data Output.*
Request To Send Control Output / Handshake signal.*
Receive Asynchronous Data Input.*
Clear to Send Control input / Handshake signal.*
Configurable CBUS I/O Pin. Function of this pin is configured in the device internal EEPROM. Factory default
pin function for the MM232R module is 12MHz Clock output. See CBUS Signal Options,
Table 2.*
Configurable CBUS I/O Pin. Function of this pin is configured in the device internal EEPROM. Factory default
pin function for the MM232R module is SLEEP# - Goes low during USB suspend mode. Typically used to
power down an external TTL to RS232 level converter I.C. in USB to RS232 converter designs. This pin is the
FT232R’s CBUS4 See CBUS Signal Options,
Table 2.*
Can be used by an external device to reset the FT232R. If not required can be left unconnected, or pulled up
to VCCIO.
Configurable CBUS I/O Pin. Function of this pin is configured in the device internal EEPROM. Factory default
pin function for the MM232R module is PWREN# - Goes low after the device is configured by USB, then high
during USB suspend. Can be used to control power to external logic P-Channel logic level MOSFET switch.
Enable the interface pull-down option when using the PWREN# pin in this way. See CBUS Signal Options,
Table 2.*
Module ground supply pins
Module 3.3V - 5.25V power supply input. To power the module from the 5V supply on USB bus connect pins
15 (USBPWR) and 14 (VCC50) together.
5V Power output USB port. For a low power USB bus powered design, up to 100mA can be sourced from the
5V supply on the USB bus. A maximum of 500mA can be sourced from the USB bus in a high power USB bus
powered design. Connect to Pin 14 (VCC50) to power the MM232R module from the USB bus.
USB Cable shield.
5
6
7
8
9
10
TXD
RTS#
RXD
CTS#
CLK12
SLEEP#
Output
Output
Input
Input
Output
Output
11
12
RESET#
PWREN#
Input
Output
13
14
15
GND
VCC5O
USBPWR
GND
PWR
Output
16
SHEILD
GND
* 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.
MM232R Mini USB-Serial UART Development Module Datasheet Version 1.00
© Future Technology Devices International Ltd. 2005
FTDI [ FUTURE TECHNOLOGY DEVICES INTERNATIONAL LTD. ]
