UCS1651S

Preliminary

LINEAR INTEGRATED CIRCUIT

UNISONICTECHNOLOGIESCO.,LTD

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www.unisonic.com.tw

QW-R103-103.f



FUNCTIONAL DESCRIPTION(Cont.)

(4) Constant Output Power Limit

When the primary current, across the primary wind of transformer, reaches the limit current, the output GATE

Higher input line voltage will result in a larger additional current and hence the output power limit is also higher than

that under low input line voltage. To compensate for this output power limit variation across a wide AC input range,

reduces the total PWM turn-on time and makes the output power equal to that of low line input. This proprietary

internal compensation ensures a constant output power limit for a wide AC input voltage range (90VAC to 264VAC).

(5) Protection section

The IC takes on more protection functions such as OLP, OVP and OTP etc. In case of those failure modes for

OLP

OVP

Fig.5 OLP case

Fig.6 OVP case

OTP