Either of the three channels of the LT3496 can drive eight 500mA LEDs in series, enabling them to drive 24 500mA LEDs with 96% efficiency.
The LT3496 senses the output current at the high-voltage side of the LED, so it can be step-down, buck-boost or boost configuration. The user can set the output current range for each channel through an external sense resistor.
Each of the three independent driver channels utilizes an internal 750mA, 45V NPN switch and has a built-in gate driver for PMOS disconnect.
Each channel of the LT3496 can be operated with a separate True Color PWM signal, allowing each channel to be dimmed at a ratio of up to 3,000:1.
The constant current mode architecture ensures stable operation over a wide range of supply and output voltages. The frequency adjustment pin allows the user to set the frequency between 330kHz and 2.1MHz for optimum efficiency and minimizes external component size. .
The LT3496's thermally enhanced 4mm x 5mm QFN package provides a fairly small layout area for 50W LED applications. Other features include open LED protection and overheating limits.
In addition to the H-grade version, there are E and I grades. All versions of the electrical specifications are E and I grades can be operated at 125 Â°C maximum junction temperature. The H-grade version is tested to operate at 150Â°C junction temperature and is ideal for automotive and industrial applications with high ambient temperatures.
Linear Technology has released the H-grade version of the LED driver LT3496. This 2MHz DC/DC converter is specifically designed to operate as a three-channel constant current LED driver.