10/20

●Operation of Each Block

・AMP

optimization helps to realize rapid transient response, and to support the use of ceramic capacitors on the output. AMP input

voltage ranges from GND to 2.7V, while the AMP output ranges from GND to VCC. When EN is OFF, or when UVLO is

active, output goes LOW and the output of the NchFET switches OFF.

・EN

The EN block controls the regulator’s ON/OFF state via the EN logic input pin. In the OFF position, circuit voltage is

maintained at 0μA, thus minimizing current consumption at standby. The FET is switched ON to enable discharge of the

electrical connection is required (e.g. between the VCC pin and the ESD prevention diode), module operation is

independent of the input sequence.

reset is triggered and output continues.

・CURRENT LIMIT

When output is ON, the current limit function monitors the internal IC output current against the parameter value. When

current exceeds this level, the current limit module lowers the output current to protect the load IC. When the overcurrent

state is eliminated, output voltage is restored to the parameter value. However when output voltage falls to or below the

SCP startup voltage, the SCP function becomes active and the output switches OFF.

・NRCS (Non Rush Current on Start-up)

The soft start function enabled by connecting an external capacitor between the NRCS pin and ground. Output ramp-up

A (TYP) constant current source to charge the external capacitor. Output start time is calculated via the formula below.

・TSD (Thermal Shut down)

The shutdown (TSD) circuit automatically is latched OFF when the chip temperature exceeds the threshold temperature

after the programmed time period elapses, thus serving to protect the IC against “thermal runaway” and heat damage.

Because the TSD circuit is intended to shut down the IC only in the presence of extreme heat, it is crucial that the Tj (max)

parameter not be exceeded in the thermal design, in order to avoid potential problems with the TSD.

・SCP

the GND short has been detected and the programmed delay time has elapsed, output is latched OFF.

It is also effective

formula below.

20uA