FT232RQ R FTDI, Future Technology Devices International Ltd, FT232RQ R Datasheet - Page 32

• Manufacturer Part Number: FT232RQ R
• Description: IC USB TO SERIAL UART 32-QFN
• Manufacturer: FTDI, Future Technology Devices International Ltd
• Series: USBmadeEZ-UARTr

Specifications of FT232RQ R

• Features: USB to UART
• Number Of Channels: 1, UART
• Fifo's: 256 Byte
• Protocol: RS-232, RS-422, RS-485
• Voltage - Supply: 3.3 V ~ 5.25 V
• With Auto Flow Control: Yes
• With Modem Control: Yes
• With Cmos: Yes
• Mounting Type: Surface Mount
• Package / Case: 32-QFN
• For Use With: 768-1023 - MOD USB RS232 DEV/EVAL FT232RL768-1022 - MODULE USB - SERIAL MODULE MINI768-1021 - MODULE MINI DEVELOPMENT FT232RQ768-1019 - MODULE USB-SER UART FT232 24-DIP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 768-1008-2; FT232RQ R

7.6 Using the External Oscillator
The FT232R defaults to operating using its own internal oscillator. This requires that the device is
powered with VCC(min)=+4.0V. This supply voltage can be taken from the USB VBUS. Applications which
require using an external oscillator, VCC= +3.3V, must do so in the following order:
The FT232R will fail to operate when the internal oscillator has been disabled, but no external oscillator
has been connected.
1. When device powered for the very first time, it must have VCC > +4.0V. This supply is available
2. The EEPROM must then be programmed to enable external oscillator. This EEPROM modification
3. The FT232R can then be powered from VCC=+3.3V and an external oscillator. This can be done
from the USB VBUS supply = +5.0V.
cannot be done using the FTDI programming utility, MPROG. The EEPROM can only be re-
configured from a custom application. Please refer to the following applications note on how to do
this:
http://www.ftdichip.com/Documents/AppNotes/AN_100_Using_The_FT232_245R_With_External_
Osc(FT_000067).pdf
using a link to switch the VCC supply.
Copyright © 2010 Future Technology Devices International Limited
FT232R USB UART IC Datasheet Version 2.07
Document No.: FT_000053
Clearance No.: FTDI# 38
32