AP65101

Document number: DS38098 Rev. 2 - 3

2 of 14

www.diodes.com

December 2016

© Diodes Incorporated

AP65101

NOT RECOMMENDED FOR NEW DESIGN

Pin Descriptions

Pin

Name

Pin Number

Function

IN

1

Power Input. IN supplies the power to the IC, as well as the step-down converter switches. Drive IN with a 4.5V

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.

GND

2

Ground

SW

3

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.

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

E

+

-

+

-

+

-

+

1.1V

0.3 V

INTERNAL

REFERENCE

Logic

0.8V

+

-

Internal

SS

OSCILLATOR

CURRENT

SENSE

AMPLIFIER

OVP

RAMP

CLK

CURRENT

COMPARATOR

FB

EN

0.8 V

GND

SW

BST

IN

500KHz

0.3V

1.1V

Vcc

REGULATOR

5

6

6

4

3

2

1