3.4

Undervoltage lockout UVLO

The undervoltage lockout (UVLO) circuit allows to turn off the regulator element if the input voltage drops below

the internal threshold, Vs UVLO, avoiding undesired unknown output state during low input voltage. When the input

voltage is above the Vs UVLO threshold, the regulating element is again turned on. If the input voltage has a

negative transient which drops below the UVLO threshold and recovers, the regulator turns off and powers up

with a normal power-up sequence once the input voltage is above the required levels.

Figure 19. Undervoltage lock out on output voltage

Vs

VS UVLO

Vo

Hysteresis

Not in scale

L99VR03

Applicationinformation

DS14803 - Rev 2

page 12/28