Suitable for high current LED applications multi topology 40V, 4.5A LED driver

Linear Technology Corporation (Linear Technology), 4.5A launched two 40V DC/DC converter LT3478 and LT3478-1, the two devices with a constant current driving high current LED. The voltage range from 2.8V to 36V is suitable for a wide variety of applications including automotive, industrial and architectural lighting. In the boost mode, the LT3478/-1 can be driven with a 12V input up to 6 series of 700mA LED, which makes the device very suitable for automotive display backlighting applications. LT3478-1 uses an internal current sense resistor to limit the output current to 1A, while the LT3478 uses an external sense resistor to maximize the LED current to 4.5A. These two devices are used to enhance the thermal resistance of the TSSOP-16E package, in the boost mode aging rate of up to 90%.

These devices have TrueColor PWM dimming function, providing constant LED color in the dimming range up to 3000:1, the fixed frequency, current mode architecture can maintain stability in the power supply device and a wide output voltage range. The frequency adjustment pins of these devices allow the user to program in the 200kHz to 2.25MHz frequency range, thus optimizing the efficiency and minimizing the component size.

LT3478/-1 in the high voltage side of the LED output current detection, can achieve buck, buck - boost and boost configuration. A two CNTRL pin can be used to the maximum current programming of LED, another can be used to reduce the temperature increase of LED the maximum current programming, thus maximizing LED utilization and improve the overall reliability. Other features include inrush current protection, LED open circuit protection and programmable soft start.

LT3478EFE and LT3478EFE-1 are thermally enhanced 16 lead TSSOP-16E package, available from stock. Two versions are priced at $3.60 per piece. Extended temperature range "I" version LT3478IFE and LT3478IFE-1 also available from stock. In 1000 pieces for the bulk purchase, each price starts at $4.32.

LT3478 and LT3478-1 * True Color performance summary: PWM dimming provides constant LED Color * in the dimming range up to 3000:1 wide input voltage range: 2.8V to 36V* 4.5A, 60m, 42V * Omega internal switch to buck mode boost, or buck boost LED* driver integrated resistor for inductors and current LED detection of LED Trojan programming current: 100mA to 1050mA (LT3478-1), (10mV to 105mV) /RSENSE (LT3478) * LED programming current with temperature rise and soft start reducing power input inductor * * separate programmable * surge current protection

Source: electronic system design