www.powerint.com

A

9/02

DI-18

10

6

8

0

0.1

0.3

0.5

0.7

Output Current (A)

0

2

4

V

V

V

V

0.6

0.4

0.2

For the latest updates, visit our Web site: www.powerint.com

Power Integrations reserves the right to make changes to its products at any time to improve reliability or manufacturability.

Power Integrations does not assume any liability arising from the use of any device or circuit described herein, nor does it convey any

license under its patent rights or the rights of others. The products and applications illustrated herein may be covered by one or more U.S.

and foreign patents or potentially by pending U.S. and foreign patent applications assigned to Power Integrations. A complete list of Power

Integrations’ patents may be found at www.powerint.com.

The PI Logo, TOPSwitch, TinySwitch and EcoSmart are registered trademarks of Power Integrations, Inc.

PI Expert is a trademark of Power Integrations, Inc. ©Copyright 2002, Power Integrations, Inc.

WORLD HEADQUARTERS

AMERICAS

Power Integrations, Inc.

San Jose, CA 95138 USA

Customer Service:

Phone:

+1 408-414-9665

Fax:

+1 408-414-9765

e-mail: usasales@powerint.com

CHINA

Power Integrations International

Holdings, Inc.

China

Phone:

+86-755-8367-5143

Fax:

+86-755-8377-9610

e-mail: chinasales@powerint.com

SINGAPORE

Power Integrations, Singapore

Republic of Singapore 308900

Phone:

+65-6358-2160

Fax:

+65-6358-2015

e-mail: singaporesales@powerint.com

JAPAN

Power Integrations, K.K.

Keihin-Tatemono 1st Bldg.

Japan

Phone:

+81-45-471-1021

Fax:

+81-45-471-3717

e-mail: japansales@powerint.com

EUROPE & AFRICA

Power Integrations (Europe) Ltd.

United Kingdom

Phone:

+44-1344-462-300

Fax:

+44-1344-311-732

e-mail: eurosales@powerint.com

KOREA

Power Integrations

International Holdings, Inc.

Seoul, Korea

Phone:

+82-2-782-2840

Fax:

+82-2-782-4427

e-mail: koreasales@powerint.com

TAIWAN

Power Integrations

International Holdings, Inc.

Taipei, Taiwan

Phone:

+886-2-2727-1221

Fax:

+886-2-2727-1223

e-mail: taiwansales@powerint.com

INDIA (Technical Support)

Innovatech

Bangalore, India

Phone:

+91-80-226-6023

Fax:

+91-80-228-9727

e-mail: indiasales@powerint.com

APPLICATIONS HOTLINE

APPLICATIONS FAX

World Wide +1-408-414-9660

World Wide +1-408-414-9760

Table 1. Transformer Construction Information.

• To maintain the

±20% CC tolerance the primary inductance

tolerance should be tighter than

±10%.

•Minimize zero load consumption by reducing drain node

capacitance: Use double coated/grade 2 wire for primary

and do not vacuum impregnate. Avoid using an RC snubber

across the output diode.

• For resistive loads increase C3 to 1

µF (electrolytic) to

allow adequate time for start-up at full load.

• For battery loads an output

π filter is typically not required

but can be added for resistive loads to reduce switching

ripple.

• L1 can be replaced with a 22

Ω to 100 Ω fusible resistor for

lower cost but lower efficiency (~10% reduction).

• Adding a 1 mA to 2 mA pre-load reduces zero load voltage

by ~1V but increases power consumption by ~10 mW.

• Diode D6 can be replaced with a PN diode for lower cost but

reduced efficiency.

• See AN-35 and EPR-16 for more information.

Figure 3. No-load Input Power Consumption.

Core

Bobbin

Winding Details

Winding Order

(pin numbers)

Inductance

Primary Resonant

Frequency

TRANSFORMER PARAMETERS

TDK PC40 EE13,

A

2

EE13 Horizontal 8 pin

Primary: 104T, 34 AWG

Shield: 12 T, 2 x 30 AWG

Secondary: 15T, 30 AWG T.I.W.

Flux Band: 1T, 6 mm Cu foil

(T.I.W.: Triple Insulated Wire)

Secondary (5-6), tape, Shield

(3-4), tape, Primary

(4-1), tape, Flux band

(3-NC)

Primary: 2.55 mH ±10%, Leakage: 50 µH (max.)

300 kHz (minimum)

Figure 2. Load Regulation - CV/CC Characteristics with Limits.

0.3

0.2

0.15

0.25

50

100

150

200

250

300

Input Voltage (VAC)

0

0.05

0.1

85 VAC: 174 mW

115 VAC: 179 mW

185 VAC: 211 mW

230 VAC: 229 mW

265 VAC: 250 mW