DS_FT312D Datasheet, PDF (15/25 Pages) List of Unclassifed Manufacturers – Future Technology Devices International Ltd.

DS_FT312D USB ANDROID HOST IC Datasheet
Version 1.0
Document No.: FT_000816 Clearance No.: FTDI# 331
8.2 USB to RS232 Converter
5V
3V3
3V3
REGULATOR
1
2
3
4
5
SHIELD
5V Power to USB
Ferrite
Bead
27R
27R
47pF
47pF
100nF
GND
GND
3V3
100nF
+
4.7uF
VCC
VCCIO
RESET#
USBDM
USBDP
TXD
RXD
RTS#
CTS#
FT312D
TX_ACTIVE
UART_TXD
UART_RXD
UART_RTS#
UART_CTS#
TXD
RXD
RS232
LEVEL
CONVERTER
RTS
CTS
DB9
3
2
7
8
10
5
SHIELD
AVCC
USB_ERROR
VREGOUT
LED
620R
3V3
100nF
GND
GND
Figure 8.2Application Example showing USB to RS232 Converter
An example of using the FT312D as a USB to RS232 converter is illustrated in Figure 8.2. In this
application, a TTL to RS232 Level Converter IC is used on the serial UART interface of the FT312D to
convert the TTL levels of the FT312D to RS232 levels. This level shift can be done using line drivers from
a variety of vendors e.g. Zywyn.
A suitable level shifting device is the Zywyn ZT3243F which is capable of RS232 communication at up to
1000k baud.
The unused pins may be left unterminated.
Copyright © 2013 Future Technology Devices International Limited
15