www.powerint.com

DI-75

B

5/04

Power Integrations

5245 Hellyer Avenue

San Jose, California 95138

MAIN PHONE NUMBER

APPLICATIONS HOTLINE

APPLICATIONS FAX

For a complete listing of worldwide sales offices,

+1 408-414-9200

+1 408-414-9660

+1 408-414-9760

please visit www.powerint.com

The PI logo,

TOPSwitch, TinySwitch, LinkSwitch and EcoSmart are registered trademarks of Power Integrations. PI Expert and DPA-Switch

are trademarks of Power Integrations.

Copyright 2004, Power Integrations

Power Integrations may make changes to its products at any time. Power Integrations has no liability arising from your use of any information, device or circuit

described herein nor does it convey any license under its patent rights or the rights of others. POWER INTEGRATIONS MAKES NO WARRANTIES HEREIN AND

SPECIFICALLY DISCLAIMS ALL WARRANTIES INCLUDING, WITHOUT LIMITATIONS, THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A

PARTICULAR PURPOSE, AND NON-INFRINGEMENT OF THIRD PARTY RIGHTS. The products and applications illustrated herein (including circuits external to the

products and transformer construction) 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.

For the latest updates, visit

www.powerint.com

Typicalapplicationsarechargersforcellphones,PDAs,portable

audio devices and shavers or power sources embedded within

homeappliancesand consumerelectronics,such asTVstandby

and bias supplies.

Figure 3. No Load Input Power Consumption.

Figure 2. Load Regulation–CV/CC Characteristics.

TRANSFORMER PARAMETERS

Core Material

TDK PC40 EE13,

AL = 185 nH/T2

Bobbin

EE13 Horizontal 8 pin

Winding Details

Bias: 39T, 34 AWG

Primary: 114T, 35 AWG

Shield: 13T, 2 x 31 AWG

Secondary: 12T, 26 AWG

Winding Order (pin

number)

Bias: (1-2), tape

Primary: (4-3), tape

Shield: (3-open), tape

Secondary: (7-6), tape

Primary Inductance 2.40 mH

Primary Resonant

Frequency

300 kHz (minimum)

7

5

6

Load (mA)

0

1

2

3

4

400

300

200

100

0

600

500

MIN

MAX

85 VAC

115 VAC

230 VAC

265 VAC

300

200

250

0

50

100

150

180

150

120

90

0

240 270

210

Table 1. Transformer Construction Information.

Key Design Points

• Set V

• Transformer primary inductance tolerance must be

≤ ±10%, to maintain CC limit tolerances (±25%)

• To allow more time for reaching regulation at startup

(or into a fully resistive load), increase C6 to 1 µF

• If battery voltage is less than 2 V, then the LinkSwitch

will not come out of its auto-restart mode

• To lower the ripple voltage into non-battery loads, an

LC filter or LDO must be added onto the output

• Adjust output voltage by changing R8 (and/or VR1) and

adjust constant current by changing R5.