DER-40

DVD/RW HDD PSU using TOP246Y

February 22, 2005

Page 21 of 30

Power Integrations

Tel: +1 408 414 9200 Fax: +1 408 414 9201

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Input Voltage

Efficiency

90Vac

76.4%

265Vac

78.2%

9.3

Standby Input Power

With E-load at 1W condition, 12VSB @ 2.5mA, 5VSB @20mA, Power Block 2 is loaded

@340mW.

Input Voltage

Input Power

110 Vac

836mW

230 Vac

860mW

9.4

Peak Load Margin

A Flyback power supply has lowest peak power capability at minimum AC voltage. The

DVD/R unit has very fluctuating power requirements, which are difficult to characterize. It

draws maximum power when switching signal inputs or inserting the DVD tray. A good test

for peak power margin is to see the minimum AC voltage that the unit can operate

normally. The unit is powered up at, and operated at a reduced AC input voltage. The unit

is cycled through different modes of operation – startup, eject, load, play, record, etc. The

DVD/RW HDD functions normally.

Input voltage

Result

75Vac

PASS

75 Vac is a very good result and implies there is plenty of margin for peak power capability.