UC3848L-S08-R datasheet(8/11 Pages) ETL

8 / 11 page

UC3848

LINEAR INTEGRATED CIRCUIT

UNISONICTECHNOLOGIESCO.,LTD

8 of 11

www.unisonic.com.tw

QW-R103-033.F

FUNCTIONAL DESCRIPTION(Cont.)

(7)Protection section (Cont.)

OLP

After soft-start phase end, IC will shutdown driver if over load state occurs for continual TD-OLP. OLP function will

not inactive during soft-start phase. OLP case as followed FIG. 6. The test circuit as followed FIG.8. TD-OLP=5.53×TSS.

OVP

There are two kinds of OVP circuits, the first OVP function are enabled only when VSS<VSS (DEACT) &

VFB>VFB(OLP) during soft-start phase. During above condition, driver will be shutdown if over voltage state occurs

(VCC>VOVP1) for continual a blanking time. The first OVP function will not inactive after soft-start phase. The second

OVP will shutdown the switching of the power MOSFET whenever VCC>VOVP2. The first OVP case as followed FIG.7.

The test circuit as followed FIG. 9.

FIG.6 OLP case

FIG.7 OVP case

FIG.8 OLP test circuit

FIG.9 OVP test circuit

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