MIC2012 Micrel MIC2012/MIC2072
USB Power Controller General Description Features The MIC2012 is a dual channel USB power switch designed to
support the power distribution requirements for USB Wakeup
from the ACPI S3 state. The MIC2012 will directly switch its
two outputs between a 5V main supply and a 5V auxiliary
supply normally provided in ATX style power supplies.
The MIC2012 will adjust its current-limit threshold according
to the ACPI state it is in. In the normal active S0 state the current-limit is set at 500mA minimum per channel satisfying the
USB continuous output current speciп¬Ѓcation. In the S3 state
the current-limit can be reduced to only 100mA per channel
to minimize the current that is supplied by the auxiliary supply
thereby ensuring that voltage regulation is maintained even
during fault conditions.
The MIC2012 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.
The MIC2072 option latches the output off upon detecting
an overcurrent condition for more than 5ms minimum. The
output can be reset by either toggling the EN inputs of the
MIC2072-1, -2 or by removing the load. Latching the output …