Linear Technology announces the H-grade version of the LT3517. The LT3517 is a high side current sense DC/DC converter designed to drive high current LEDs at constant current. Its 3V to 30V input voltage range with transient protection to 40V makes it ideal for a range of applications, including automotive, industrial and architectural lighting. The H-grade version operates with a junction temperature up to 150ºC, compared to the E- and I-grade versions' 125ºC maximum junction temperature. All electrical specifications are identical for the E-, I- and H-grade versions. The H-grade parts are tested and guaranteed to the maximum junction temperature of 150ºC, making them ideal for automotive and industrial applications which are subjected to high ambient temperatures.
The LT3517 can drive up to four 300mA white LEDs from a nominal 12V input, making it ideal for applications such as automotive display backlighting. The LT3517 senses output current at the high side of the LED, enabling buck, buck-boost or boost configurations. The device delivers efficiencies up to 90% in boost mode from a 4mm x 4mm QFN package. The LT3517 offers True Color PWM™ dimming which ensures constant LED color with dimming ranges of up to 5,000:1. For less demanding dimming requirements, the CTRL pin can be used to provide 10:1 analog dimming. Its fixed frequency, current mode architecture offers stable operation over a wide range of supply and output voltages. A frequency adjust pin enables the user to program the frequency between 250kHz and 2.5MHz to optimize efficiency while minimizing external component size.