MIC2010_06 Datasheet, PDF (15/16 Pages) Micrel Semiconductor – USB Power Controller

MIC2012
dead short on the output.
Fault Status Output
The FAULT signal is an active-low output with an open-drain
or weak pull-up configuration. FAULT is asserted (active-low)
when either an overcurrent or thermal shutdown condition
occurs. In the case of an overcurrent condition, FAULT will
be asserted only after the flag response delay time, t_DLY, has
elapsed. This ensures that FAULT is asserted only upon valid
overcurrent conditions and that erroneous error reporting is
eliminated. For example, false overcurrent conditions can
occur during hot-plug events when a highly capacitive load
is connected and causes a high transient inrush current that
Micrel
exceeds the current-limit threshold. The FAULT response
delay time t_DLY is typically 10ms.
Undervoltage Lockout
Undervoltage lockout (UVLO) prevents the output MOSFET
from turning on until the AUX input exceeds approximately
3.5V. UVLO ensures that the output MOSFETs remain off
to prevent high transient inrush current due to stray or bulk
load capacitance. This helps to ensure that the power supply
EN
(MIC2010-2)
V_OUT
FAULT
Overcurrent Fault
Thermal Shutdown
Reached
Figure 6. MIC2012 System Timing
EN
(MIC2070-2)
V_OUT
FAULT
Overcurrent Fault
Load Removed–
Output Reset
Figure 7. MIC2072 System Timing—
Output Resets When Load is Removed
January 2005
15
MIC2012/2072