Reference Design Creates Complete LCD Power System
Combining the main system power with the backlight inverter, the GreenPoint open reference design for LCD TV power supplies from On Semiconductor eliminates a complete power conversion stage, improving overall system efficiency, simplifying the design and reducing the bill of materials. The 180-W design meets IEC 61000-3-2 for harmonic content requirements, and exceeds global standby requirements with a typical standby power consumption of 400 mW with a 50-mW load. 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. A proprietary variable-frequency control architecture achieves up to 60 W output capability from the flyback stage while meeting the standby requirements, thus eliminating the need for a dedicated standby supply. The design was completed in conjunction with Microsemi Corporation.