Document No.: FT_000329
FT232BL/BQ USB UART IC Datasheet Version 2.2
Clearance No.: FTDI# 171
Pin No.
25
Name
TXD
Type
Output
Input
Description
Transmit Asynchronous Data Output.
24
RXD
Receiving Asynchronous Data Input
23
RTS#
CTS#
DTR#
DSR#
DCD#
Output
Input
Request to Send Control Output / Handshake Signal.
Data Terminal Ready Control Output / Handshake Signal.
Clear To Send Control Input / Handshake Signal.
Data Set Ready Control Input / Handshake Signal.
Data Carrier Detect Control Input.
22
21
Output
Input
20
19
Input
Ring Indicator Control Input. When remote wake up is enabled in the internal
EEPROM taking RI# low (20ms active low pulse) can be used to resume the PC
USB host controller from suspend.
18
RI#
Input
16
TXDEN
Output
Enable Transmit Data for RS485.
Table 3.4 UART Interface Group
Pin No.
Name
Type
Description
EEPROM – Chip Select. For 48MHz operation pull EECS to GND using a 10K resistor.
For 6MHz operation no resistor is required. Tri-State during device reset. **Note 1
32
EECS
I/O
Clock signal to EEPROM. Tri-State during device reset, else drives out. Adding a
10K pull down resistor onto EESK will cause the FT232B to use USB Product ID
6004 (hex) instead of 6001 (hex). All of the other USB device descriptors are
unchanged.**Note 1
1
EESK
Output
EEPROM – Data I/O Connect directly to Data-In of the EEPROM and to Data-Out of
the EEPROM via a 2.2K resistor. Also, pull Data-Out of the EEPROM to VCC via a
10K resistor for correct operation. Tri-State during device reset. **Note 1
2
EEDATA
I/O
Table 3.5 EEPROM Interface Group
Pin No.
Name
Type
Description
Goes Low during USB Suspend Mode. Typically used to power-down an external
TTL to RS232 level converter IC in USB RS232 converter designs
10
SLEEP#
Output
Goes Low after the device is configured via USB, then high during USB suspend.
Can be used to control power to external logic using a P-Channel Logic Level
MOSFET switch. Enable the Interface Pull-Down Option in EEPROM when using the
PWREN# pin in this way.
15
14
PWREN#
PWRCTL
Output
Input
Bus Powered – Tie Low / Self Powered – Tie High (to VCCIO)
Table 3.6 Power Control Group
**Note 1 – During device reset, these pins are tri-state but pulled up to VCC via internal 200K resistors.
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9
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