Reference Design for an Integrated LCD TV Power and Inverter Supply
ON Semiconductor has released its latest GreenPoint open reference design for LCD TV power supplies. This 180W High Voltage LCD Integrated Power Supply (HV-LIPS) combines the main system power with the backlight inverter. By implementing an architecture where the inverter is directly powered from the 400 volt (V) PFC rail, the reference design eliminates a complete power conversion stage, improving overall system efficiency, simplifying the design and reducing the bill of materials. The design supports the need for higher efficiency power supplies to meet the active and standby power requirement of the ENERGY STAR 3.0 TV standard that went into place in November 2008.
ON Semiconductor’s reference design for LCD TV power supplies meets IEC 61000-3-2 harmonic content requirements, and exceeds global standby requirements with typical standby power consumption of 400 milliwatts (mW) with a 50 mW load. ON Semiconductor was able to leverage a proprietary variable frequency control architecture to achieve up to 60 W output capability from the flyback stage while meeting the standby requirements, thus eliminating the need for a dedicated standby supply.
“Our customers have expressed interest in the design, as HV-LIPS power supplies are starting to enter the mainstream market for 32 inch and larger LCD TVs”, said Bill Schromm, senior vice president and general manager of ON Semiconductor’s Computing and Consumer Group. “The reference design merges the power supply with the inverter onto a single PCB with a maximum height of 25 mm, to meet the tight form factor constraints of LCD TVs.”
The reference design addresses all functional blocks of the HV-LIPS LCD TV power supply, including power factor correction; control, signal, and audio power; high voltage backlight inverter; and CCFL drive and current balancing. The design utilizes several of ON Semiconductor’s newest power management devices and draws from its leading discrete component portfolio to achieve superior power efficiency performance. The design was completed in conjunction with Microsemi Corporation (Nasdaq: MSCC) to incorporate its latest CCFL backlight inverter and JIN Current Balancer technology for CCFL.
Microsemi and ON Semiconductor have collaborated to provide customers with an optimized, turnkey LCD TV backlight solution that brings outstanding performance and functionality to eco-friendly LCD TVs, said Tom Kapucija, director of marketing in the Analog Mixed Signal Group of Microsemi. The LX6503 delivers synchronization and lamp current accuracy while supporting a broader range of signal frequencies and sources than alternative solutions for mainstream HV-LIPS applications. This gives HV/LIPS display users a superior visual experience whether they are watching TV broadcasts or playing DVD or Blu-Ray content. The integration of the LX6503 CCFL inverter controller into ON Semiconductor's GreenPoint 400V HV-LIPS reference design creates a complete solution for our customers.
ON Semiconductor has a complete documentation package for the HV-LIPS LCD TV reference design, including description, schematics, bill-of-materials, Gerber files, and evaluation guidelines. The documentation package is available at www.onsemi.com/powersupplies, as are links to relevant industry information and other supporting information.