AP5100

1.2A Step-Down Converter with 1.4MHz Switching

Frequency

AP5100

4 of 12

MARCH 2010

Document number: DS32130 Rev. 1 - 2

www.diodes.com

Pin Descriptions

Pin Name

Pin #

Description

BST

1

Bootstrap. To form a boost circuit, a capacitor is connected between SW and BST

pins to form a floating supply across the power switch driver. This capacitor is needed

range from 0.1uF to 1uF.

GND

2

Ground. This pin is the voltage reference for the regulated output voltage. All control

circuits are referenced to this pin. For this reason care must be taken in its layout.

FB

3

Feedback. To set the output voltage, connect this pin to the output resistor divider or

frequency foldback comparator lowers the oscillator frequency when the FB voltage is

below 400mV.

EN

4

On/Off Control Input. Do not leave this pin floating. To turn the device ON, pull EN

above 1.2V and to turn it off pull below 0.4V.

IN

5

Supply Voltage. The AP5100 operates from a +4.75V to +24V unregulated input. A

decoupling capacitor C1 is required to prevent large voltage spikes from appearing at

the input. Place this capacitor near the IC.

SW

6

Switch Output. This is the reference for the floating top gate driver.

Absolute Maximum Ratings

(Note 3)

Symbol

Description

Rating

Unit

ESD HBM

Human Body Model ESD Protection

3

KV

ESD MM

Machine Model ESD Protection

300

V

Supply Voltage

26

V

Switch Voltage

-0.3 to

V

Boost Voltage

V

All Other Pins

–0.3 to +6

V

Storage Temperature

-65 to +150

°C

Junction Temperature

+150

°C

Lead Temperature

+260

°C

θ

JA

Junction to Ambient Thermal Resistance (Note 4)

140

°C/W

θ

JC

Junction to Case Thermal Resistance (Note 4)

35

°C/W

Notes:

3. Exceeding these ratings may damage the device.

4. Test condition for SOT26: Measured on approximately 1” square of 1 oz copper.