MIC2010

Micrel

MIC2010/2070

8

September 2000

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 or open-drain configuration. 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

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

10ms. Since the delay timer is shared between both channels

it is possible for t

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)

Overcurrent Fault

Thermal Shutdown

Reached

FAULT

Figure 6. MIC2010 System Timing

EN

(MIC2070-2)

Overcurrent Fault

Load Removed–

Output Reset

FAULT

Figure 7. MIC2070 System Timing—

Output Resets When Load is Removed