AP63300Q/AP63301Q

Document number: DS43699 Rev. 1 - 2

3 of 22

www.diodes.com

May 2021

© Diodes Incorporated

AP63300Q/AP63301Q

Pin Descriptions

Pin Name

Pin Number

Function

FB

1

Feedback sensing terminal for the output voltage. Connect this pin to the resistive divider of the output.

See Setting the Output Voltage section for more details.

EN

2

Enable Input. EN is a digital input that turns the regulator on or off. Drive EN high to turn on the regulator and low to

turn it off. Connect to VIN or leave floating for automatic startup. The EN has a precision threshold of 1.18V for

adjusting the UVLO. See Enable section for more details.

VIN

3

Power Input. VIN supplies the power to the IC as well as the step-down converter

’s power MOSFETs. Drive VIN with

a 3.8V to 32V power source. Bypass VIN to GND with a suitably large capacitor to eliminate noise due to the

switching of the IC. See Input Capacitor section for more details.

GND

4

Power Ground.

SW

5

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.

BST

6

High-Side Gate Drive Boost Input. BST supplies the drive for the high-side N-channel power MOSFET. A 100nF

capacitor is recommended from BST to SW to power the high-side driver.

Functional Block Diagram

0.88V

OVP

+

SE = 0.84V/T

RT = 0.2V/A

FB

SW

VIN

ON

3

0.8V

VCC

+

-

1

+

+

-

+

-

+

-

OSC

VSUM

Control

Logic

0.8V

Ref

PWM

Comparator

OCP

5

6

4

OVP

+

-

CSA

BST

GND

EN

2

Error

Amplifier

500kHz

Oscillator

Internal SS

Thermal

Shutdown

TSD

COMP

VCC

Regulator

Internal

Reference

1.18V

I1

1.5μA

I2

4μA

20kΩ

+

–

Figure 4. Functional Block Diagram