BCT3220数据手册Broadchip中文资料规格书

描述 Description

The BCT3220 is a high performance whiteLED driver. The BCT3220 uses an internalresistor to set the bias current for four LEDs,which are matched to 1.5%. The BCT3220'sadvantages over ballast resistors include muchlower 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 currentfrom 2.5mA to 20mA by a serial pulse. TheDimming 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.

特性 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

应用 Application

• Cell Phones
• PDAs
• Digital Cameras, Camcorders
• Portable Instrumentation
• Battery Powered Equipment