MIC2010

MIC2010/2070 MIC2010/MIC2070 USB Power Controller Micrel General Description 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. 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. The MIC2070 option latches the output off upon detecting an overcurrent condition lasting for more than 5ms minimum. The output can be reset by either toggling the EN inputs of the MIC2070-1/-2 or by removing the load. Latching the output off provides a circuit breaker mode of operation which reduces power consumptio...