Data Sheet

ADP5138

Rev. A | Page 19 of 23

The LDO is designed to current limit when the output load

reaches the current-limit threshold. When the output load

exceeds the current-limit threshold, the output voltage is

reduced to maintain a constant current limit.

ACTIVE OUTPUT DISCHARGE

Each of the five regulators in the ADP5138 integrates a discharge

switch from the switching node to ground. This switch is turned

on when its associated ENx pin is low, which helps to discharge

the output capacitor quickly. The typical value of the discharge

switch is 64 Ω for the buck regulators and 83 Ω for the LDO

regulator.

THERMAL SHUTDOWN

In the event that the ADP5138 junction temperature exceeds

150°C, the thermal shutdown circuit turns off the device. A 15°C

hysteresis is included so that the ADP5138 does not recover from

thermal shutdown until the on-chip temperature drops below

135°C. Upon recovery, a soft start and the power-up sequence

are initiated prior to normal operation.