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NXP公司的PCA9685是16路12位PWM不是Fm+I2C总线LED控制器，每个LED输出有它独立的12位分辨率固定频率PWM控制器，工作频率从40Hz到1000Hz，占空比从0%到100%.工作电压2.3 V 到5.5 V，主要用在RGB或RGBALED驱动器，LED状态显示器，LED显示器，LCD背光和手机或手持设备的键盘背光.本文介绍了PCA9685主要特性和优势，方框图以及典型应用电路图和LCD背光应用电路图.PCA9685: 16-channel， 12-bit PWM Fm+ I2C-bus LED control☿lerThe PCA9685 is an I2C-bus controlled 16-channel LED controlleroptimized for LCD Red/Green/Blue/Amber color backlightingapplications. Each LED output has its own 12-bit resolution fixed frequency individual PWM controller that operates at aprogrammable frequency from a typical of 40 Hz to 1000 Hz with aduty cycle that is adjustable from 0 % to 100 % to allow the LED tobe set to a specific brighรtness value. All outputs are set to thesame PWM frequency.Each LED ouมtput can be off or on ， or set at itsindividual PWM controller value. The LED output driver isprogrammed to be either open-drain with a 25 mA current sinkcapability at 5 V or totem pole with a 25 mA sink， 10 mA sourcecapability at 5 V. Th☒e PCA9685 operates with a supply voltage rangeof 2.3 V to 5.5 V and the inputs and outputs are 5.5 V tolerant.LEDs can be directly connected to the LED output or controlled with external drivers and a minimum amount ofdiscrete components for larger current or higher voltage LEDs.The PCA9685 is in the new Fast-mode Plus family. Fm+ devicesoffer higher frequency and more densely populated busoperation .Although the ✍PCA9635 and PCA9685 hav