SC2041 Semtech Corporation, SC2041 Datasheet - Page 13

• Manufacturer Part Number: SC2041
• Description: HotSwitch USB Power Distribution Switch With Shutdown
• Manufacturer: Semtech Corporation

July 18, 2000
TYPICAL APPLICATIONS CIRCUITS (Cont.)
High-Power or Low-Power Bus-Powered Function:
Both low-power and high-power bus-powered functions
must draw less than 100mA at startup. At this time,
they must also present a load of less than the parallel
combination of a 44
After startup, high powered functions may then draw up
to 500mA. The circuit below utilizes the SC2041 to
provide inrush current limiting and power switching for
the internal function.
Note:
(1) 33µF output capacitor per port meets the USB specification minimum capacitance of 120µF per hub.
© 2000 SEMTECH CORP.
Upstream Port
VBUS
GND
D+
D-
C1
10uF
1
2
U1
1
2
SR05
resistor and a 10µF capacitor.
1
2
3
4
3
U2
SC5205-3.3
VIN
GND
EN BYP
4
3
VO
5
4
C2
10nF
HotSwitch™ USB Power Distribution
Switch With Shutdown
C3
4.7uF
USB Controller
D0D+
D0D-
VCC
EN
OC
Since USB is a hot insertion and removal system, USB
ports are subject to electrostatic discharge (ESD). The
SR05 provides ESD protection on the upstream data
and power lines. With proper layout the port is hard-
ened to greater than 15kV, meeting the requirements of
IEC 1000-4-2. The SC5205 LDO regulator is used to
power the hub controller from the upstream bus.
652 MITCHELL ROAD NEWBURY PARK CA 91320
R1 100k
C4
0.1uF
1
2
3
4
U3
GND
IN
IN
SHDN
SC2041
OUT
OUT
OUT
FLG
8
7
6
5
C5
10uF
SC2041
Internal Function
VCC
GND
13