AP65452

Document number: DS37305 Rev. 4 - 3

2 of 13

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October 2017

© Diodes Incorporated

AP65452

NOT RECOMMENDED FOR NEW DESIGN

USE AP65450

Pin Descriptions

Pin

Name

Pin Number

Function

SO-8EP

EN

1

Enable input. EN is a digital input that turns the regulator on or off. Drive EN high to turn on the regulator, drive it low

to turn off. Pull

up with 100kΩ resistor for automatic startup.

FB

2

Feedback Input. FB senses the output voltage and regulates it. Drive FB with a resistive voltage divider connected to

it from the output voltage.

VREG5

3

Internal power supply output pin to connect an additional capacitor. Connect a

1μF (typical) capacitor as close as

possible to the VREG5 and GND. This pin is not active when EN is low.

SS

4

Soft-start control input pin. SS controls the soft start period. Connect a capacitor from SS to GND to set the soft-start

period.

GND

5

Ground pin is the main power ground for the switching circuit.

SW

6

Power Switching Output. SW is the switching node that supplies power to the output. Connect the output LC filter

from SW to the output load. Note that a capacitor is required from SW to BS to power the high-side switch.

BS

7

Bootstrap pin. A bootstrap capacitor is connected between the BS pin and SW pin. The voltage across the bootstrap

capacitor drives the internal high-

side NMOS switch. A 0.1μF (typical) capacitor is required for proper operation.

VIN

8

Supply input pin. A capacitor should be connected between the VIN pin and GND pin to keep the DC input voltage

constant.

EP

Connect the exposed thermal pad to GND on the PCB.

Functional Block Diagram

Figure 2 Functional Block Diagram