FT232BM USB UART ( USB - Serial) I.C.
•
EEPROM Interface
Though the FT232BM will work without the optional
EEPROM, an external 93C46 (93C56 or 93C66)
EEPROM can be used to customise the USB VID,
PID, Serial Number, Product Description Strings
and Power Descriptor value of the FT232BM for
OEM applications. Other parameters controlled
by the EEPROM include Remote Wake Up,
Isochronous Transfer Mode, Soft Pull Down on
Power-Off and USB 2.0 descriptor modes.
The EEPROM should be a 16 bit wide
configuration such as a MicroChip 93LC46B or
equivalent capable of a 1Mb/s clock rate at VCC =
4.35V to 5.25V. The EEPROM is programmable-
on board over USB using a utility available from
FTDI’s web site (http://www.ftdichip.com). This
allows a blank part to be soldered onto the PCB
and programmed as part of the manufacturing and
test process.
If no EEPROM is connected (or the EEPROM
is blank), the FT232BM will use its built-in
default VID, PID Product Description and Power
Descriptor Value. In this case, the device will not
have a serial number as part of the USB descriptor.
4.0
Device Pin-Out
13
26
3
30
6
3V3OUT
A
V
V
C
V
C
C
V
C
C
XTOUT
V
C
C
I
O
TXD
RXD
25
EECS
AVCC
TEST
AGND
24
XTIN
VCC
TXD
8
USBDM
RTS#
CTS#
23
22
7
USBDP
DTR#
DSR#
21
32
EESK
EEDATA
VCC
RESET#
RSTOUT#
3V3OUT
USBDP
USBDM
8
9
1
25
24
5
20
FTDI
FT232BM
XXYY
16
17
RXD
RTS#
CTS#
DTR#
DSR#
DCD#
RI#
GND
RSTOUT#
RESET#
DCD#
RI#
19
4
18
27
XTIN
TXDEN
TXLED#
16
12
28
XTOUT
EECS
EESK
EEDATA
TEST
A
G
N
D
29
RXLED#
11
32
1
PWRCTL
PWREN#
SLEEP#
G
N
D
9
G
N
D
17
14
2
31
15
10
RXLED#
PWRCTL
SLEEP#
TXLED#
PWREN#
VCCIO
Figure 1
Pin-Out
(LQFP-32 Package )
DS232B Version 1.8
TXDEN
GND
Figure 2
Pin-Out
(Schematic Symbol )
Page 7 of 25
© Future Technology Devices Intl. Ltd. 2005
FTDI [ FUTURE TECHNOLOGY DEVICES INTERNATIONAL LTD. ]
