SC2041IS.TR View Datasheet(PDF) - Semtech Corporation

Part Name

Description

MFG CO.

SC2041IS.TR

HotSwitch™ USB Power Distribution Switch With Shutdown

Semtech Corporation 

Prev 11 12 13 14

HotSwitch™ USB Power Distribution

Switch With Shutdown

SC2041

July 18, 2000

TYPICAL APPLICATIONS CIRCUITS (Cont.)

Bus-Powered Hub, Ganged-Port Power

Management:

A bus-powered hub distributes power and data from an

input port to downstream ports. It must supply a contin-

uous 100mA of current to each downstream port. A

bus-powered hub must be able to switch power to

downstream ports to prevent illegal device hook-up.

Inrush current limiting is also required to prevent power

supply drooping. The circuit below utilizes the SC2041

to provide ganged port power switching, inrush current

limiting and overcurrent protection for maximum port

protection. In a ganged switch configuration, all ports

are switched simultaneously. Under fault conditions,

the USB controller will remove power to all of the

ganged ports. For individual port management,

additional SC2041s may be used.

Since USB is a hot insertion and removal system, USB

ports are subject to electrostatic discharge (ESD). The

SRDA05-4 provides ESD protection on the downstream

data and power lines. Each device will protect two USB

ports. With proper layout the port is hardened to greater

than 15kV, meeting the requirements of IEC 1000-4-2.

On the upstream port, the SR05 provides ESD protec-

tion to the above levels for one line pair. The SC5205

LDO regulator is used to power the hub controller from

the upstream bus.

D+

D-

VBUS

GND

Upstream Port

U1

11

2

2

44

3

3

SR05

C1

4.7uF

U2

1 VIN VO 5

2 GND

3 EN BYP 4

SC5205-3.3

EN

OC

OC

D0D+ OC

D0D- OC

C2

10nF

VCC

C3

4.7uF

D1D+

D1D-

D2D+

D2D-

D3D+

D3D-

D4D+

D4D-

USB Controller

R1 100k

U3 SC2041

1 GND OUT 8

2

IN

7

OUT

3 IN

OUT 6

4

5

SHDN FLG

C4

0.1uF

U4

I/O1 REF1

I/O2 REF1

I/O3 REF2

I/O4 REF2

SRDA05-4

U5

I/O1 REF1

I/O2 REF1

I/O3 REF2

I/O4 REF2

SRDA05-4

C5

33uF

C6

33uF

C7

33uF

C8

33uF

Ferrite Bead

Ferrite Bead

VBUS

D+

D-

GND

Downstream Port

Ferrite Bead

Ferrite Bead

VBUS

D+

D-

GND

Downstream Port

Ferrite Bead

Ferrite Bead

VBUS

D+

D-

GND

Downstream Port

Ferrite Bead

Ferrite Bead

VBUS

D+

D-

GND

Downstream Port

Note:

(1) 33µF output capacitor per port meets the USB specification minimum capacitance requirement of 120µF per

hub.

© 2000 SEMTECH CORP.

12

652 MITCHELL ROAD NEWBURY PARK CA 91320

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