BCT3220
The BCT3220 is a high performance white LED driver. The BCT3220 uses an internal resistor to set the bias current for four LEDs, which are matched to 1.5%. The BCT3220's advantages over ballast resistors include much lower bias variation with supply voltage variation, significantly lower dropout voltage, and in some applications, significantly improved efficiency. The BCT3220 requires only a 50mV dropout voltage at a 20mA load on each output to match the LED brightness.
Users can easily configure the LED current from 2.5mA to 20mA by a serial pulse. The Dimming of white LEDs current can be achieved by applying a pulse signal to the EN pin. There are totally 8 steps of current could be set by users. Internal soft start circuitry effectively reduces the in-rush current while both start-up and mode transition.
FEATURES
Low 50mV Dropout at 20mA
20mA full scale current
1.5% LED Current Matching (TYP)
One Wire interface for 8-Step Brightness Control
2.7V to 5.5V Supply Voltage Range
Thermal Shutdown Protection
Low Input Noise and EMI
RoHS Compliant and 100% Lead (Pb)-Free, DFN2x2-8L Package
APPLICATIONS
Cell Phones
PDAs
Digital Cameras, Camcorders
Portable Instrumentation
Battery Powered Equipment
