MIC2012 Datasheet, PDF (9/10 Pages) Micrel Semiconductor – USB Power Controller Advance Information

MIC2012
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
exceeds the current-limit threshold. The FAULT response
delay time t_DLY is typically 10ms.
Micrel
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
voltage regulation is preserved and also prevents possible
damage to sensitive components.
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
September 2000
9
MIC2012/2072