Diodes AP1635 User Manual

AP1635

PWM/PFM DUAL MODE STEP-DOWN DC/DC

CONVERTER

Features

• Input voltage range: 2.2V~5V (V

• Oscillator frequency: 700KHz (Typ.)

• Internal reference: 1.0V (Typ.)

• High efficiency: 93% (Typ.)

• Current limit and thermal shutdown protection

• Lead Free Package: SOP-8L

• SOP-8L: Available in “Green” Molding Compound

(No Br, Sb)

• Lead Free Finish/ RoHS Compliant (Note 1)

OUT

type)

Applications

• Electronic Information Organizers

• Palmtops

• Cellular and portable phones

• Portable Audio Systems

• Various Multi-function Power Supplies

Ordering Information

AP 1635 S X - 13

General Description

The AP1635 series are multi-functional step-down DC/DC
converters with built-in speed, low ON resistance drivers. It is
capable to deliver more than 1.2A output current with external
coil, diode and ca pacitor.

Output voltage is set-up by the external resistors. (±2.5%
accuracy). The 700KHz AP1635 that can work out with small
value external components comes out more compact board.

The device switches to and works under PFM mode with light
loads. It keeps at high efficiency for both light loads and large
output current.

AP1635 can be soft-start with a proper capacitor connected
between CE/SS pin and ground. The stand-by current is less
than 6uA when CE/SS pin is at “LOW” status. The device is
forced to switch off as the voltage at that pin is lower than the
stipulated voltage.

Package PackingLead Free

S : SOP-8L

L : Lead Free

G : Green

Device

AP1635SL-13 S SOP-8L 2500/Tape & Reel -13

Lead-free

Package

Code

Packaging

(Note 2)

AP1635SG-13 S SOP-8L 2500/Tape & Reel -13

Notes: 1. EU Directive 2002/95/EC (RoHS). All applicable RoHS exemptions applied. Please visit our website at
http://www.diodes.com/products/lead_free.html

2. Pad layout as shown on Diodes Inc. suggested pad layout document AP02001, which can be found on our website at

http://www.diodes.com/datasheets/ap02001.pdf

.

.

AP1635 Rev. 4 1 of 8 FEBRUARY 2009

www.diodes.com © Diodes Incorporated

13 : Tape & Reel

13” Tape and Reel

Quantity Part Number Suffix

Pin Assignments

( Top View )

AP1635

PWM/PFM DUAL MODE STEP-DOWN DC/DC

CONVERTER

FB

CE/SS

SVcc

PVcc

1

2

3

4

SOP-8L

8

GND

GND

7

SW

6

5

SW

Pin Descriptions

Pin Name Pin No. Description

FB 1 Feedback pin

Chip Enable/ Soft Start:

CE/SS 2

SVcc 3
PVcc 4 IC power supply pin

SW 5/6

GND 7/8 GND Pin

H: Enable
L: Disable
IC signal power supply pin, add a 20Ω re sistor to P Vcc a nd a

0.1µF capacitor to GND.
Switch Pin. Connect external inductor/diode here. Minimize

trace area at this pin to reduce EMI.

AP1635 Rev. 4 2 of 8 FEBRUARY 2009

www.diodes.com © Diodes Incorporated

Block Diagram

AP1635

PWM/PFM DUAL MODE STEP-DOWN DC/DC

CONVERTER

SVcc

FB

Phase

Compensation

Current Limit

PVcc

+

ERR
AMP

-

Soft

Start

CE/SS GND

Vref with

CE

Absolute Maximum Ratings (T

Symbol Parameter Ratings Units

VCC/SVCC VIN Pin Voltage -0.3 ~ 5.0 V

VSW SW Pin Voltage -0.3 ~ VIN+0.3 V

VFB FB Pin Voltage -0.3 ~ VIN+0.3 V

V

CE/SS Pin Voltage -0.3 ~ VIN+0.3 V

CE/SS

PD Continuous Total Power Dissipation Internal limited

T

Operating Ambient Temperature -25 ~ +80 °C

OPR

T

Storage Temperature -40 ~ +125 °C

STG

PWM/PFM

Controller

=25°C)

A

+

-

Comparator

Ramp Wave

Generator,

OSC

SW

PWM

AP1635 Rev. 4 3 of 8 FEBRUARY 2009

www.diodes.com © Diodes Incorporated