DocumentCode :
2332018
Title :
Effectiveness of FRFET® MOSFETs for the CCFL inverters in LCD TVs
Author :
Yeon, Jae-Eul ; Kim, Cha-Kwang ; Myung-Sub Jung ; Kim, Woo-Taek ; Cho, Kyu-Min ; Kim, Hee-Jun
fYear :
2008
fDate :
11-13 June 2008
Firstpage :
1351
Lastpage :
1355
Abstract :
For the backlighting of most LCD panels such as TVs and monitors today, CCFL (cold cathode fluorescent lamp) is widely used because it can provide both low cost manufacturing and high quality color gamut. To illuminate the CCFL, half-bridge or full-bridge resonant inverters are necessary. Although resonant inverters can work under the ZVS condition when the PFM (pulse frequency modulation) method is applied, most major LCD manufacturers adopt the PWM (pulse width modulation) method to control their LCDpsilas CCFL inverter because not only the color gamut might be varied but also its stability will be unstable when the inverter is operated by the PFM method due to its incremental resistance according to the varying the switching frequency. In the cases where CCFL inverter works with PWM method, the hard switching operation is inevitable and the additional diodes must be required because the reverse recovery behavior of the MOSFETpsilas body diode is inferior to FRD (fast recovery diode), which causes a large amount of switching loss and it will even make the system failure due to the shoot-through current. In this paper, a newly improved FRFET MOSFET with superior reverse recovery characteristics is introduced and the experimental results for applying it to 42rdquo LCD TV are presented. From these results, the validity of the new FRFET has been verified. The reverse recovery time is shorter than 40 ns and irr is also much smaller than the typical power MOSFETs, which are sufficient to prevent the MOSFETpsilas failures without the external diodes in CCFL BLU (back light unit) system.
Keywords :
MOSFET; bridge circuits; cold-cathode tubes; fluorescent lamps; liquid crystal displays; pulse frequency modulation; resonant invertors; television displays; CCFL inverters; FRFET MOSFET; LCD TV; LCD panels; PWM method; ZVS; back light unit system; cold cathode fluorescent lamp; fast recovery diode; full-bridge resonant inverters; pulse frequency modulation; pulse width modulation; reverse recovery characteristics; switching frequency; Cathodes; Computer displays; Costs; Diodes; Fluorescent lamps; MOSFETs; Manufacturing; Pulse inverters; Pulse width modulation inverters; Resonant inverters; CCFL inverter; FRFETs; LCD BLU; MOSFET failure; Resonant Inverter;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Power Electronics, Electrical Drives, Automation and Motion, 2008. SPEEDAM 2008. International Symposium on
Conference_Location :
Ischia
Print_ISBN :
978-1-4244-1663-9
Electronic_ISBN :
978-1-4244-1664-6
Type :
conf
DOI :
10.1109/SPEEDHAM.2008.4581133
Filename :
4581133
Link To Document :
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