APS39903

Document number: DS37226 Rev. 2 - 2

1 of 17

www.diodes.com

October 2014

© Diodes Incorporated

APS39903

A Product Line of

Diodes Incorporated

PUMP EXPRESS

Description

The APS39903 is a high accuracy and low cost switching mode

power supply switcher for battery charger/adapter applications. It is

consists of a primary side regulation controller and a high voltage

transistor. The controller regulates the output voltage and current in

the primary side by piece-wise Pulse Frequency Modulation (p-PFM)

in discontinuous conduction mode (DCM). The switcher uses adaptive

source current to optimize driving current to reduce driving loss. The

system operating frequency reduces linearly from heavy load to light

load in each interval of the p-PFM, and enters constant current mode

when the load current is equal to the maximum system output current.

The output voltage and output current limit of APS39903 can be

adjusted based on the patterns of load current aligned to MTK Pump

Express protocol.

The APS39903 provides operating frequency Jitter function from light

to full load range to improve the power supply EMI performance. The

APS39903 also has built-in fixed cable voltage drop compensation

(6% of nominal system output voltage) and adjustable line voltage

compensation.

The APS39903 can work individually to achieve Ultra-Low standby

power under 5V output.

The APS39903 is packaged in SO-7.

Applications



Adapters/Chargers

Pin Assignments

(Top View)

1

2

3

4

7

6

5

FB

VCC

GND

C

C

CS

CPC

SO-7

Features

 Ultra-Low Standby Power Consumption

 Built-in NPN Transistor with 700V

CBO

 Valley-turn On to Reduce Switching Loss and Benefit for EMI

 Piece-wise Frequency Reduction to Enhance Conversion Efficiency

and Suppress Audio Noise

 ±5% Constant Voltage Accuracy for 5V Output

 Audio Noise Suppression

 Open Circuit Protection (OCkP)

 Current Sense Resistor Short Protection

 Over Voltage Protection (OVP)

 Over Temperature Protection (OTP)

 Short Circuit Protection (SCP) with Hiccup

 Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2)

 Halogen and Antimony Free. “Green” Device (Note 3)

Notes:

1. No purposely added lead. Fully EU Directive 2002/95/EC (RoHS) & 2011/65/EU (RoHS 2) compliant.

2. See http://www.diodes.com/quality/lead_free.html

for more information about Diodes Incorporated’s definitions of Halogen- and Antimony-free, "Green"

and Lead-free.

3. Halogen- and Antimony-

free "Green” products are defined as those which contain <900ppm bromine, <900ppm chlorine (<1500ppm total Br + Cl) and

<1000ppm antimony compounds.