Microsemi has announced the LX27901, a revolutionary non-dissipative LED backlight driver for LCD TV applications. The backlight driver provides LED driving capabilities in TVs based on the LCD integrated power supply architecture, which combines a TV's main power supply together with the LED driver on a PCB.
The backlight driver includes three selectable drive modes, the company's patented ACU_BRITE algorithm to provide high-accuracy dimming over an operating range, synchronous regulation to reduce the number of power conversion stages and accurate current matching through the company's non-dissipative balancing technology. The driver also features 0.8A source and sink drive capacity; on chip 5.25V regulator; direct connection to input voltage up to 27V; user selectable dimming mode control; robust protection during abnormal open and short LED conditions; compensated external and internal PWM dimming operation; dedicated fault indication; and LED current and voltage monitoring. The driver is RoHS-compliant and halogen free.
The backlight driver utilises the company's EcoBrite technology, combining the TV power supply and LED driver into a single efficient unit, eliminating the need for a DC/DC boost regulator, says the company. EcoBrite technology is also claimed to eliminate the need for a dissipative current source due to its patented reactive LED string balancing feature. In addition, the company's Acu-Brite dimming technology provides non-dissipative and accurate dimming at low current levels. The backlight driver is available in a plastic, 16pin SOIC surface mounted package.