●Description
●The LM3532 is a 500-kHz fixed frequency asynchronous boost converter which provides the power for 3 high-voltage, low-side current sinks. The device is programmable over an I2C-compatible interface and has independent current control for all three channels. The adaptive current regulation method allows for different LED currents in each current sink thus allowing for a wide variety of backlight and keypad applications.
●Features
●• Drives up to 3 Parallel High-Voltage LED Strings at 40 V Each With up to 90% Efficiency
●• 0.4% Typical Current Matching Between Strings
●• 256 Level Logarithmic and Linear Brightness Control With 14-Bit Equivalent Dimming
●• I2C-Compatible Interface
●• Direct Read Back of Ambient Light Sensor Via 8-bit ADC
●• Programmable Dual Ambient Light Sensor Inputs With Internal Sensor Gain Selection
●• Dual External PWM Inputs for LED Brightness Adjustment
●• Independent Current String Brightness Control
●• Programmable LED Current Ramp Rates
●• 40-V Overvoltage Protection
●• 1-A Typical Current Limit
●Applications
●• Power Source for White LED Backlit LCD Displays
●• Programmable Keypad Backlight
