Power Integrations

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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

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DISCLAIMS ALL WARRANTIES INCLUDING, WITHOUT LIMITATION, 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

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B

12/04

DI-66

Table 1. Transformer Construction Information.

Core

Bobbin

Winding Details

Winding Order

(pin numbers)

Primary Inductance

Primary Resonant

Frequency

Leakage Inductance

TRANSFORMER PARAMETERS

Samwha EER3016S-PL-7

10 Pin, EER3016S

1/2 Primary: 28 T, 26 AWG

Bias: 7T, 2 x 26 AWG

12 V Secondary, 4T, 2 x 25 AWG

Triple Insulated Wire

5 V Secondary: 3T, 3 x 25 AWG

Triple Insulated Wire

1/2 Primary: 24T, 26 AWG

1/2 Primary: 2-5, tape 1L

Bias: 3-4, tape 2L

12 V Secondary: 10-6,7

5 V Secondary: 6,7-8,9, tape 2L

1/2 Primary: 5-1, tape 3L

919 µH ±10%

1.1 MHz (Min)

18 µH (Max)

0

0.2

0.3

0.1

0.4

0.5

0.6

0.7

Output Power (W)

0.6

0.7

0.3

0.4

0.5

0.2

1

1.1

0.8

0.9

1.2

230 VAC

115 VAC

-20

-10

0

10

20

30

40

50

60

70

80

0.15

1

10

70

Frequency (MHz)

(QP)

(AV)

Quasi-Peak Scan

Average Scan

Figure 3. P

on 12 V Output.

Figure 2. Conducted EMI, CISPR22B Limits, Maximum Load, Secondary

Return Connected to Safety Ground, 230 VAC Input.

Effective EMI filtering is accomplished with only five parts

(L1, CX1, CY1-CY3), due to the built-in frequency jitter

function of TOPSwitch-GX.

Key Design Points

• Use 66 kHz operation to reduce standby power loss.

• To reduce the number of primary turns required for

66 kHz operation, the A

Recommended cores are EER3016S and PQ2620.

• Split-primary transformer construction should be used to

keep leakage inductance to a minimum.

• Use an RCD snubber with the normal recovery diode. Size

resistors R2 and R3 for the highest value that ensures

adequate drain voltage margin under overload conditions at

high line.