FT245BL/TR FTDI, FT245BL/TR Datasheet - Page 17

• Manufacturer Part Number: FT245BL/TR
• Description: IC, USB FIFO INTERFACE, 480MBPS, LQFP-32
• Manufacturer: FTDI

Specifications of FT245BL/TR

• Usb Type: FIFO
• Usb Version: 1.1, 2.0
• Data Rate: 480Mbps
• No. Of Ports: 2
• Supply Voltage Range: 4.35V To 5.25V
• Operating Temperature Range: 0°C To +70°C
• Digital Ic Case Style: LQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

7.3
Figure 7
USB Bus Powered Configuration
Figure 7 illustrates a typical USB bus powered configuration. A USB Bus Powered device gets its power from the USB
bus. Basic rules for USB Bus power devices are as follows –
a) On plug-in, the device must draw no more than 100mA
b) On USB Suspend the device must draw no more than 500uA.
c) A Bus Powered High Power Device (one that draws more than 100mA) should use the PWREN# pin to keep the
d) A device that consumes more than 100mA can not be plugged into a USB Bus Powered Hub
e) No device can draw more that 500mA from the USB Bus.
The power descriptor in the EEPROM should be programmed to match the current draw of the device.
A Ferrite Bead is connected in series with USB power to prevent noise from the device and associated circuitry (EMI)
being radiated down the USB cable to the Host. The value of the Ferrite Bead depends on the total current required by
the circuit – a suitable range of Ferrite Beads is available from Steward (www.steward.com) for example Steward Part
# MI0805K400R-00 also available as DigiKey Part # 240-1035-1.
current below 100mA on plug-in and 500uA on USB suspend.
Connector
USB "B"
DS245BL Version 1.6
USB Bus Powered and Self Powered Configuration
0.1uF
1
2
3
4
0.1uF
VCC
Decoupling Capacitors
10nF
+
10uF
Ferrite Bead
27R
© Future Technology Devices Intl. Ltd. 2005
27R
1k5
VCC
VCC
33nF
FT245BM
FT245BL USB FIFO ( USB - Parallel ) I.C.
4
6
8
7
5
3v3OUT
USB DM
USB DP
RSTOUT#
RESET#
3
V
C
C
26
C
C
V
13
O
V
C
C
I
G
N
D
470R
9
G
N
D
17
30
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C
C
A
V
29
A
G
N
D
0.1uF