MIC2505/2506

Micrel

MIC2505/2506

10

April 1998

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.

ON/OFF

OVERCURRENT

MIC2505-2/-1

3.3V USB Controller

D+

D–

GND

D+

D–

GND

100k

MIC5203-3.3

MIC5207-3.3

LDO Regulator

IN

OUT

GND

33µF

Ferrite

Bead

D+

D–

GND

D+

D–

V+

EN

OUT

FLG

IN

GND

OUT

GATE

IN

Bold lines indicate

0.1" wide, 1-oz. copper

high-current traces.

Downstream

USB

Port 1

500mA max.

33µF

D+

D–

GND

Data

D+

D–

GND

33µF

33µF

0.01µF

0.01µF

0.01µF

0.01µF

4.7

µF

1.0

µF

GND

0.1µF

4.45V to 5.25V

3.5A max.

(+)

(–)

33µF

Downstream

USB

Port 2

500mA max.

Downstream

USB

Port 3

500mA max.

Downstream

USB

Port 4

500mA max.

Figure 4. Ganged-Switch Self-Powered Hub