Milpitas, Calif.—Linear Technology's LT3476 DC/DC converter chip contains four independent driver channels that can each drive up to eight 1-amp LEDs in series. Thus the LT3476 can drive up to thirty-two 1-amp LEDs for 100-watt LED applications while delivering efficiencies up to 96 percent.
Each channel provides True Color PWM dimming circuitry, which facilitates a dimming ratio of up to 1000:1. The chip's fixed-frequency, current-mode architecture ensures stable operation over a wide range of supply voltages (2.8 to 16 volts). A frequency-adjust pin enables the user to program the frequency between 200 kHz and 2 MHz to optimize efficiency while minimizing external component size.
The LT3476 senses output current at the high side of the LED, enabling buck, buck-boost, or boost configurations. The user programs the output current range of each channel using an external resistor. Each of the driver channels utilizes an internal 1.5-amp, 36V NPN switch. Other features include open LED protection and thermal limiting.
Click here for the product datasheet. The LT3476EUHF, available from stock in a thermally enhanced 38-lead, 5-by-7 mm DFN package, is priced from $4.64 each in 1k pieces.
Linear Technology, 1-800-4LINEAR, www.linear.com