Milpitas, Calif. Linear Technology has introduced the LT3593, a high-efficiency constant current white LED driver packaged in a 2 x 2-mm DFN (or ThinSOT) package. The white LED driver features a unique high-side LED current sense topology that enables the LED cathode to be connected directly to ground, creating a single-wire current source. A single digital control pin enables set-and-forget LED dimming with ratios as high as 32:1.
The LT3593 is designed to drive up to 10 white LEDs from a single Li-ion cell at efficiencies over 80%. It operates from an input voltage from 2.7 V to 5.5 V, optimizing it for single cell Li-ion and multi-cell alkaline/NiCd/NiMH sources. Its 1-MHz constant switching frequency allows the use of small, low-profile inductors and capacitors while keeping input and output noise low and well controlled, Linear said. The combination of high efficiency, low noise and extremely small total solution footprint makes the LT3593 suitable for handheld applications that require up to 10 white LEDs for backlighting.
The LT3593 ensures the uniform brightness of each LED by acting as a constant current source, delivering the same current to each white LED, regardless of fluctuations in the LED's forward voltage drop, which varies with temperature, manufacturing tolerances and age. The driver uses a single-wire digital serial interface to deliver 32:1 linear brightness control. Other features include output disconnect in shutdown, open LED protection and a ±5% reference accuracy.
Pricing: Starts at $1.40 each in quantities of 1,000.
Availability: From stock.
Product information: LT3593
Linear Technology, www.linear.com