DER-9

Generic PCB for DVD Player using TinySwitch-II

February 4, 2004

Page 8 of 26

Power Integrations

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4.8

Floating +3V and Its Bias Option

D11 and C14 rectify and filter the AC voltage to generate a floating +3V. R10 and R11

are the option if the floating voltage needs a reference voltage. The level of the reference

voltage can be adjusted by assigning different resistance value to R10 and R11.

4.9

–12V Linear Regulator Option

-12V is regulated through the coupling between -22V and 5V windings. Because its load

usually is quite light, which is about tens of milliamps, the regulation should be enough for

most applications. The option of a linear regulator U4 is provided if the tight regulation is

preferred for the –12V.