AP3211

Document number: DS41396 Rev. 2 - 2

2 of 11

www.diodes.com

September 2018

© Diodes Incorporated

AP3211

Pin Descriptions

Pin Number

Pin Name

Function

1

BS

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.

2

GND

Ground pin

3

FB

Feedback pin. This pin is connected to an external resistor divider to program the system

protection.

4

EN

Control input pin. Forcing this pin above 1.5V enables the IC. Forcing this pin below 0.4V

shuts down the IC. When the IC is in shutdown mode, all functions are disabled to decrease

the supply current below 1µA.

5

IN

Supply input pin. A capacitor should be connected between the IN pin and GND to keep the

DC input voltage constant.

6

SW

Power switch output pin. This pin is connected to the inductor and bootstrap capacitor.

Functional Block Diagram

REFERENCE

VOLTAGE

ERR AMP

PWM

COMPARATOR

FB

GND

EN

VDD/VDD1

REGULATOR

IN

OSC

1.4MHz/

400KHz

RAMP

GENERATOR

R

R

S

OSC

Q

SWITCH/LDO

SW

CS

CL

BOOSTRAP

REGULATOR

BS

HICCUP

FB

CL

SS

SS

2A/V

SCHOTTKEY

1pF

220k

27pF

5

2

4

3

6

1

1M

3.3V