Linear introduced constant current white LED driver

Linear Technology Corporation (Linear Technology Corporation) x 2mm DFN launched by 2mm (or ThinSOT) encapsulation efficiency constant current white LED driver LT3593. The device has a unique high side LED current sensing topology, so that the LED cathode can be directly grounded to form a single line current source. In addition, a digital control pin provides up to 32:1 dimming ratio "once and for all" LED dimming function. LT3593 uses a single lithium ion battery to drive up to 10 white LED at a rate of more than 80%. It operates from 2.7V to 5.5V input voltage, optimized for a single lithium ion and multi base / Ni / Ni MH battery power supply. The 1MHz constant switching frequency allows the use of tiny and flat inductor and capacitor, while keeping the input and output noise is very low and well controlled. High efficiency, low noise and minimal overall solution for board area makes the LT3593 very suitable for applications requiring up to 10 white LED backlighting applications.

By acting as a constant current source and conveying the same current to each white LED, LT3593 to ensure that the brightness of each LED, but not affected by the fluctuation of LED forward voltage drop, the voltage drop will change because of temperature, manufacturing tolerance and aging condition. LT3593 provides linear brightness control for 32:1 with a single line digital serial interface. Other features include shutdown output disconnect, LED open circuit protection and + 5% reference accuracy.

Performance summary

With 3V power supply drive up to 10 white LED

Single pin down and current programming

Shutdown LED disconnect

Single line 32:1 brightness control range

VIN range: 2.7V to 5.5V

Full scale output current accuracy is + 5%

Low shutdown current: 3uA

1MHz switching frequency

Requires only 1uF output capacitors

Flat 6 lead DFN (2mm x x 0.75mm) and 6 lead SOT-23 package (2mm)