FT240XQ-R FTDI, FT240XQ-R Datasheet - Page 22

• Manufacturer Part Number: FT240XQ-R
• Description: USB Interface IC USB to Parallel FIFO IC QFN-24
• Manufacturer: FTDI

Specifications of FT240XQ-R

• Rohs: yes
• Product: USB 2.0
• Data Rate: 12 Mbps, 480 Mbps
• Interface Type: USB
• Operating Supply Voltage: 2.97 V to 5.5 V
• Operating Supply Current: 8 mA to 8.4 mA
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Package / Case: QFN-24
• Tradename: X-Chip

6
The following sections illustrate possible USB power configurations for the FT240X. The illustrations have
omitted pin numbers for ease of understanding since the pins differ between the FT240XS and FT240XQ
package options.
All USB power configurations illustrated apply to both package options for the FT240X device. Please refer
to Section 0 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 FT240X 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 MTP memory of the FT240X 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 FT240X 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 # MI0805K601R-10.
i)
ii)
iii)
iv)
v)
USB Power Configurations
SHIELD
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 the
PWREN# 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.
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1
2
3
4
100nF
GND
10nF
Copyright © 2013 Future Technology Devices International Limited
Ferrite
Bead
47pF
VCC
+
GND
4.7uF
GND
VCC
47pF
FT240X USB 8-BIT FIFO IC Datasheet
GND
Document No.: FT_000626 Clearance No.:
27R
27R
100nF
USBDM
VCC
USBDP
3V3OUT
RESET#
VCCIO
FT240X
Version 1.3
FTDI# 259
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