MAX8879 用于背光/闪光灯/RGB LED驱动的安全定时器 MAX8879概述 The MAX8879 features an internally trimmed reference to set the maximum LED current. An I²C serial port is used for on/off control and setting the LED currents in 32 linear steps for main, sub/RGB, and movie. When using the RGB indicator, the I²C port provides 32k colors and programmable ramp-up/down rates. The camera flash for flash-mode operation is enabled by an active-low signal on the active-low FSH pin. A safety timer is activated on the falling edge of active-low FSH, which has an I²C-adjustable (programmable) period of no timer, 0.5s, 1.0s, or 2.0s (default). If the safety timer period expires, both flash and movie modes are disabled. MAX8879关键特性

Guaranteed 610mA Continuous Drive Capability

• 4 LEDs at 30mA Each for Main Display
• 3 LEDs at 30mA Each for Sub or RGB
• 400mA Total for Flash

2-Wire I²C Serial Port

• 5-Bit (32-Step) Linear Dimming
• 32k Colors
• Ramp-Up/Down Rates

92% Peak/83% Avg Efficiency (P_LED/P_BATT)

Adaptive 1x/1.5x/2x Mode Switchover

0.3% (typ) LED Current Accuracy and Matching

Low Input Ripple and EMI

Low 0.1µA Shutdown Current

Output Overvoltage Protection

I²C Programmable Flash Safety Timer

Thermal Derating Function Protects LEDs

24-Pin, 4mm x 4mm Thin QFN Package

MAX8879应用/使用

蜂窝电话与智能电话
LED显示器，多达11个LED
PDA、数码相机、便携式摄像机

MAX8879 pdf datasheet