LP3944

LP3944 www.ti.com SNVS264A – MAY 2004 – REVISED APRIL 2013 LP3944 RGB/White/Blue 8-LED Fun Light Driver Check for Samples: LP3944 FEATURES 1 2 Internal Power-on Reset Active Low Reset Internal Precision Oscillator Variable Dim Rates (from 6.25 ms to 1.6s; 160 Hz–0.625 Hz) APPLICATIONS Customized Flashing LED Lights for Cellular Phones Portable Applications Digital Cameras Indicator Lamps General Purpose I/O Expander Toys KEY SPECIFICATIONS 8 LED Driver (Multiple Programmable States—On, Off, Input, and Dimming at a Specified Rate) 8 Open Drain Outputs Capable of Driving up to 25 mA per LED DESCRIPTION LP3944 is an integrated device capable of independently driving 8 LEDs. This device also contains an internal precision oscillator that provides all the necessary timing required for driving each LED. Two prescaler registers along with two PWM registers provide a versatile duty cycle control. The LP3944 contains the ability to dim LEDs in SMBUS/I2C applications where it is required to cut down on bus traffic. Traditionally, to dim LEDs using a serial shift register such as 74LS594/5 would require a large amount of traffic to be on the serial bus. LP3944 instead requires only the setup of the frequency and duty cycle for each output pin. From then on, only a single command from the host is required to turn each individual open drain output ON, OFF, or to cycle a programmed frequency and duty cycle. Maximum output sink current is 25 mA per pin and 200 mA...