AP65111

Document number: DS39153 Rev. 3 - 3

2 of 14

www.diodes.com

January 2018

© Diodes Incorporated

AP65111

Pin Descriptions

Pin

Name

Pin Number

Function

TSOT26

IN

1

Power Input. IN supplies the power to the IC, as well as the step-down converter switches. Drive IN with a 6V to

16V power source. Bypass IN to GND with a suitably large capacitor to eliminate noise on the input to the IC.

See Input Capacitor.

SW

2

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.

GND

3

Ground

BST

4

High-Side Gate Drive Boost Input. BS supplies the drive for the high-side N-Channel MOSFET a 0.01µF or

greater capacitor from SW to BS to power the high side switch.

EN

5

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

turn it off. Attach to IN with a 100kΩ pull up resistor for automatic startup.

FB

6

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

connected to it from the output voltage. The feedback threshold is 0.8V. See Setting the Output Voltage.

Functional Block Diagram

1

IN

5

EN

2

SW

6

FB

3

GND

Internal

Reference

0.4V

0.8V

1.1V

Vcc

Regulator

+

-

+

-

+

-

-

+

1.1V

0.4V

+

0.8V

Internal SS

Error

Amplifier

OVP

PWM

Comparator

Oscillator

500KHz

+

Logic

4

BST

Ref

62pF

650k

1pF

OCP

UVP

SE=0.9V/T

RT=0.22V/A