MIC2010_05 Datasheet, PDF (8/13 Pages) Micrel Semiconductor – USB Power Controller

MIC2010/2070
off. This time duration will be shortest in the case of a dead
short on the output.
Fault Status Output
The FAULT signal is an active-low output with a weak pull-
up. FAULT is asserted 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. The FAULT response
delay time t_DLY is typically 10ms. Since the delay timer is
shared between both channels it is possible for t_DLY to be
Micrel
extended by an amount equal to the difference between the
occurrence of the over-current event in both channels.
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. MIC2010 System Timing
EN
(MIC2070-2)
V_OUT
FAULT
Overcurrent Fault
Load Removed–
Output Reset
Figure 7. MIC2070 System Timing—
Output Resets When Load is Removed
M9999-101104
8
January 2005