Date: 21/10/2009

Synchronous step-down DC/DC converter from Linear for high current LEDs

Linear has announced the LT3743, a synchronous step-down DC/DC converter that offer constant current to drive high current LEDs with an input operating voltage range from 5.5V to 36V. The LT3743 is suitable for the applications such as industrial, DLP projection and architectural lighting.

The LT3743 provides up to 20A of LED current from a 12V input, delivering in excess of 80 Watts. In pulsed LED applications, it can deliver up to 40A of LED current or 160 Watts from a 12V input. A 95% of its efficiency eliminates the need for external heat sinking and simplify the thermal design. A frequency adjust pin enables the frequency between 100kHz and 1MHz to optimize efficiency while minimizing external component size.

The key features of the LT3743 are,

PWM dimming provides up to 3000:1 dimming ratio
CTRL_SEL dimming provides up to 3000:1 dimming ratio between any current
three-state current control for color mixing
+6% current regulation accuracy
Average current mode control
2us maximum recovery time between any current regulation state
1uA shutdown current
Output voltage regulation & Open-LED protection

Package:
LT3743EUFD: 28-pin 4mm x 5mm QFN package
LT3743EFE: Thermally enhanced TSSOP-28 package

Price:
LT3743EUFD: Starts at each $4.80 for 1k pieces
LT3743EFE: Starts at each $4.95 for 1k pieces

Extended temperature versions, or "I" grades, namely the LT3743IUFD and LT3743IFE are also available. Pricing starts at each $5.65 and $5.82 for 1k pieces.

Availability: All versions are available from stock.
For more details visit www.linear.com

Editorial Product Rating: Average Plus