描述 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.The main features of the LM3532 include dual ambient light sensor inputs each with 32 internal voltage setting resistors, 8-bit logarithmic and linear brightness control, dual external PWM brightness control inputs, and up to 1000:1 dimming ratio with programmable fade in and fade out settings.The LM3532 is available in a 16-pin, 0.4-mm pitch thin DSBGA package. The device operates over a 2.7-V to 5.5-V input voltage range and the ?40°C to +85°C temperature range.

特性 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