MIC2010/2070
Micrel
MIC2010/MIC2070
USB Power Controller
General Description
Features
• Compliant to USB power distribution specifications
• Two completely independent switches
• Integrated switching matrix supports ACPI S0/S3 state
transitions without external FET circuits
• Make-before-break switching ensures glitch-free
transitions
The MIC2010 is a dual channel USB power switch designed
to support the power distribution requirements for USB
Wakeup from the ACPI S3 state. The MIC2010 will directly
switch its two outputs between a 5V main supply and a
5V auxiliary supply normally provided in ATX style power
supplies.
• No back-feed of auxiliary supply onto main supply
during standby mode
• Bi-level current-limit preserves auxiliary supply voltage
regulation in standby mode
• Thermally isolated channels
• Thermal shutdown protection
• Fault status outputs with filter prevents false assertions
during hot-plug events
• Circuit breaker options with auto-reset (MIC2070)
• Undervoltage lockout
The MIC2010 will adjust its current-limit threshold according
to the ACPI state it is in. In the normal active ACPI S0 state
the current-limit is set at 500mA minimum per channel
satisfying the USB continuous output current specification.
In the S3 state the current-limit can be reduced to a value
determined by an external resistor to minimize the current
that is supplied by the auxiliary supply, thereby ensuring that
voltage regulation is maintained even during fault conditions.
The MIC2010 provides make-before-break switching to
ensure glitch-free transitions between the S3 and S0 states.
Each channel is also thermally isolated from the other so that
a fault in one channel does not effect the other. FAULT status
output signals are also provided indicating overcurrent and
thermal shutdown conditions.
• UL File #179633
Applications
• Desktop PCs
The MIC2070 option latches the output off upon detecting an
overcurrent condition lasting for more than 5ms minimum.
TheoutputcanberesetbyeithertogglingtheENinputsofthe
MIC2070-1/-2 or by removing the load. Latching the output
off provides a circuit breaker mode of operation which
reduces power consumption during fault conditions.
• Notebook PCs
• Notebook docking stations
• LAN Servers
• PC motherboard
Typical Application
ATX Power Supply
5V MAIN
VBUS
5V STANDBY
Downstream
USB
Port 1
D+
MIC2010-1P/-2P
D–
MAIN
AUX
100µF
GND
OUT1
OUT2
ON/OFF 1
ON/OFF 2
EN1
VBUS
D+
EN2
Downstream
USB
Port 2
S3# CONTROL
RSET1
S3#
D–
FAULT1
FAULT1
100µF
GND
RSET2
82801AA or Equivalent
GND
SLP S3#
SLP S5#
Overcurrent Port 1
Overcurrent Port 1
OC0
OC1
Figure 1. USB Wakeup From ACPI S3 System Diagram
UL Recognized Component
Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
January 2005
1
M9999-101104