Triple Output LED Driver Offers 3000:1 True Color PWM Dimming
Linear Technology Corporation announces the LT3492 , a 2.1MHz DC/DC converter designed to operate as a three-channel constant current LED driver. Each of the LT3492's three channels can drive up to ten 300mA LEDs in series, enabling it to drive up to 30 x 300mA LEDs at efficiencies up to 96%. All three channels are operated by an independent True Color PWM™ signal, enabling each to be dimmed independently to ratios as high as 3,000:1. A fixed frequency, current mode architecture ensures stable operation over a wide range of supply and output voltages. A frequency adjust pin enables the user to program the frequency between 330kHz and 2.1MHz to optimize efficiency while minimizing external component size. The LT3492's thermally enhanced 4mm x 5mm QFN (or thermally enhanced TSSOP) package provides a highly compact solution footprint for up to 50W LED applications.
The LT3492  senses output current at the high side of the LED, enabling buck, buck-boost or boost configurations. With an external sense resistor, the user can program the output current range of each channel. Each of the three independent driver channels utilizes an internal 600mA, 60V NPN switch and has a built-in gate driver for PMOS disconnect. Other features include open LED protection and thermal limiting.
The LT3492EUFD  is available in a thermally enhanced 28-lead 4mm x 5mm QFN package, and the LT3492EFE  is available in a thermally enhanced TSSOP-28 package. Pricing starts at $3.70 and $3.85 each, respectively in 1,000 piece quantities. Industrial grade versions, the LT3492IUFD  and LT3492IFE , are tested and guaranteed to operate from -40ºC to 125ºC operating junction temperature and are priced at $4.35 and $4.53 each, respectively in 1,000 piece quantities. All versions are available from stock. For more information, visit www.linear.com .
About Linear Technology
Linear Technology Corporation, a manufacturer of high performance linear integrated circuits, was founded in 1981, became a public company in 1986 and joined the S&P 500 index of major public companies in 2000. Linear Technology products include high performance amplifiers, comparators, voltage references, monolithic filters, linear regulators, DC-DC converters, battery chargers, data converters, communications interface circuits, RF signal conditioning circuits, µModule® products, and many other analog functions. Applications for Linear Technology's high performance circuits include telecommunications, cellular telephones, networking products such as optical switches, notebook and desktop computers, computer peripherals, video/multimedia, industrial instrumentation, security monitoring devices, high-end consumer products such as digital cameras and MP3 players, complex medical devices, automotive electronics, factory automation, process control, and military and space systems.