Green Design

Triple Step-Down LED Driver

The LT3597 from Linear Technology ((Milpitas, CA) is a 60-V triple step-down LED driver capable of achieving 10,000:1 digital PWM dimming at 100 Hz with fast NPN current sources driving up to 10 LEDs in each channel. LED dimming can also be achieved via analog control of the CTRL1-3 pin.

The step-down switching frequency is programmed between 200 kHz and 1 MHz. The frequency is also synchronizable to an external clock. The LT3597 provides maximum LED brightness while adhering to manufacturers’ specifications for thermal derating. The derate temperature is programmed by placing a negative temperature coefficient (NTC) resistor on the master control pin.

The LT3597 adaptively controls VOUT in order to achieve optimal efficiency. Other features include: 2% LED current matching between channels, open LED reporting, shorted LED protection, programmable LED current, and programmable temperature protection. Applications include LED billboards and signboards, LED displays, and large screen display LED backlighting.

(Linear Technology)