 |
Electronic Components Datasheet Search |
|
|
Electronic Components Datasheet Search |
|
UC3848G-S08-R Datasheet(PDF) 5 Page - Unisonic Technologies |
|
||||||||||||||||||||||||||||||
UC3848G-S08-R Datasheet(HTML) 5 Page - Unisonic Technologies |
|
|
5 / 11 page 
UC3848 LINEAR INTEGRATED CIRCUIT UNISONICTECHNOLOGIESCO.,LTD 5 of 11 www.unisonic.com.tw QW-R103-033.F FUNCTIONAL DESCRIPTION The internal reference voltages and bias circuit work at VCC> VTHD (ON), and shutdown at VCC<VCC (MIN). (1) Soft-Start When every IC power on, driver output duty cycle will be decided by voltage VSS on soft-start capacitor and VCS on current sense resistor at beginning. After VSS reach 4.2V, the whole soft-start phase end, and driver duty cycle depend on VFB and VCS. The relation among VSS, VFB and VOUT as followed FIG.3. Furthermore, soft-start phase should end before VCC reach VCC (MIN) during VCC power on. Otherwise, if soft-start phase remain not end before VCC reach VCC (MIN) during VCC power on, IC will enter auto-restart phase and not set up VOUT. So the value of CSS should be between 0.1μFand 4.7μF. Finally soft-start also set OVP1 active phase. OVP1 active phase between 0 and VSS(DEACT), OVP1 will not be sensed after VSS reach VSS(DEACT).The Soft-start phase TSS：TSS = 23.8×CSS (ms) (Example: CSS=0.47μF, then TSS=23.8×0.47=11.2ms). FIG.3 Soft-start phase |
|
English ▼
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
