MIC2505/2506
Micrel
Applications Information
USB Application
Figure 4 depicts a low cost and robust implementation of a
four-port, self-powered USB hub circuit employing ganged
overcurrent protection.
(+)
4.45V to 5.25V
3.5A max.
(–)
V
BUS
D+
D–
GND
Ferrite
Bead
33µF
MIC5203-3.3
MIC5207-3.3
LDO Regulator
IN
OUT
GND
4.7
µF
D+
D–
GND
1.0
µF
100k
3.3V USB Controller
V+
ON/OFF
OVERCURRENT
MIC2505-2/-1
EN
FLG
GND
GATE
OUT
IN
OUT
IN
0.1µF
33µF
0.01µF
V
BUS
D+
D–
GND
Downstream
USB
Port 2
500mA max.
33µF
0.01µF
V
BUS
D+
D–
GND
Downstream
USB
Port 1
500mA max.
Bold
lines indicate
0.1" wide, 1-oz. copper
high-current traces.
33µF
0.01µF
V
BUS
D+
D–
GND
Downstream
USB
Port 3
500mA max.
V
BUS
D+
0.01µF
33µF
D–
GND
Downstream
USB
Port 4
500mA max.
Data
Figure 4. Ganged-Switch Self-Powered Hub
MIC2505/2506
10
April 1998
MICREL [ MICREL SEMICONDUCTOR ]
