A new synchronous buck-boost DC/DC LED driver and voltage controller has been released by Linear Technology, which can deliver over 100W of LED power.
Its 4.7V to 60V input voltage range makes it ideal for a wide variety of applications, including automotive, industrial and architectural lighting. Similarly, its output voltage can be set from 0V to 60V, enabling the LT3791 to drive a wide range of LEDs in a single string.
The internal four-switch buck-boost controller operates from input voltages above, below or equal to the output voltage, ideal for applications such as automotive, where the input voltage can vary dramatically during stop/start, cold crank and load dump scenarios.
Transitions between buck, pass-through and boost operating modes are seamless, offering a well-regulated output even with wide variations of supply voltage. The design of the device utilises three control loops to monitor input current, LED current and output voltage.
The driver uses four external switching MOSFETs and delivers from 5W to over 100W of continuous LED power with efficiencies up to 98.5 percent. LED current accuracy of 6 percent ensures constant lighting while 2 percent output voltage accuracy enables the converter to operate as a constant voltage source. The device utilises either analogue or PWM dimming as required by the application.
Linear Technology
