FT232RL R FTDI, Future Technology Devices International Ltd, FT232RL R Datasheet - Page 23

• Manufacturer Part Number: FT232RL R
• Description: IC USB TO SERIAL UART 28-SSOP
• Manufacturer: FTDI, Future Technology Devices International Ltd
• Series: USBmadeEZ-UARTr

Specifications of FT232RL 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: 28-SSOP
• 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: 768-1007-2; FT232RL R

6
The following sections illustrate possible USB power configurations for the FT232R. The illustrations have
omitted pin numbers for ease of understanding since the pins differ between the FT232RL and FT232RQ
package options.
All USB power configurations illustrated apply to both package options for the FT232R device. Please refer
to Section 3 for the package option pin-out and signal descriptions.
6.1 USB Bus Powered Configuration
Figure 6.1 Bus Powered Configuration
Figure 6.1 Illustrates the FT232R in a typical USB bus powered design configuration. A USB bus powered
device gets its power from the USB bus. Basic rules for USB bus power devices are as follows –
The power descriptors in the internal EEPROM of the FT232R should be programmed to match the current
drawn by the device.
A ferrite bead is connected in series with the USB power supply to reduce EMI noise from the FT232R and
associated circuitry being radiated down the USB cable to the USB host. The value of the Ferrite Bead
depends on the total current drawn by the application. A suitable range of Ferrite Beads is available from
Steward (www.steward.com), for example Steward Part # MI0805K400R-10.
Note: If using PWREN# (available using the CBUS) the pin should be pulled to VCCIO using a 10kΩ
resistor.
i)
ii)
iii)
iv)
v)
USB Power Configurations
SHIELD
5
On plug-in to USB, the device should draw no more current than 100mA.
In USB Suspend mode the device should draw no more than 2.5mA.
A bus powered high power USB device (one that draws more than 100mA) should use one of
the CBUS pins configured as PWREN# and use it to keep the current below 100mA on plug-in
and 2.5mA on USB suspend.
A device that consumes more than 100mA cannot be plugged into a USB bus powered hub.
No device can draw more than 500mA from the USB bus.
Copyright © 2010 Future Technology Devices International Limited
1
2
3
4
10nF
100nF
GND
+
Ferrite
Bead
4.7uF
GND
+
Vcc
Vcc
FT232R USB UART IC Datasheet Version 2.07
GND
100nF
VCC
USBDM
USBDP
3V3OUT
VCCIO
RESET#
OSCI
OSCO
NC
NC
A
G
N
D
FT232R
G
N
D
Document No.: FT_000053
G
N
D
GND
Clearance No.: FTDI# 38
G
N
D
E
S
T
T
CBUS0
CBUS1
CBUS2
CBUS3
CBUS4
DSR#
DCD#
DTR#
RTS#
CTS#
RXD
TXD
RI#
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