Implementing Analog Dimming on the DS39xx CCFL Controllers

The DS3881, DS3882, DS3984, DS3988, DS3992 and DS3994 are controllers for cold-cathode fluorescent lamps (CCFLs) that backlight liquid crystal displays (LCDs). To achieve satisfactory visual results or conserve lamp life, dimming is required in most applications. This application note introduces two dimming approaches commonly used for CCFLs and describes how to implement analog dimming on the DS39xx CCFL controllers.