LEDs are the lighting workhorse of cell phones, MP3
players and diagnostic lights in telecom systems. Their
uses are many, from utilitarian backlighting to eye-catching
aesthetic effects such as slowly pulsing multicolor
indicators. As device designers strive to differentiate
their products on the shelf, the number and complexity of
lighting effects grows. It would seem that each new effect
requires signifi cant additional hardware, and/or complex
software, right? Actually, no, there is a way to apply these
effects to a number of LEDs with only a single driver IC.
The LTC?3219 9-output universal LED (ULED) driver
can be programmed to individually gradate, blink or
turn on nine individual LEDs using internal logic and
circuitry to drive nine 6-bit DAC-controlled LED current
sources. Because the gradation and blinking features
are controlled internally, effects can be realized without
adding ICs, extensively tying up the I2C bus or fi lling
valuable memory space with complex programming
subroutines. Any feature on any 0mA to 28mA output can
be confi gured to activate via the external enable (ENU)
pin or I2C interface.