Catalog
Complete lighting solution for smartphone handsets
Key Features
• Drives Two Parallel High-Voltage LED Strings forDisplay and Keypad LightingHigh-Voltage Strings Capable of up to 40-VOutput Voltage and up to 90% EfficiencyUp to 30 mA per Current Sink (Both Backlight andIndicator)14-Bit Equivalent Exponential Dimming With 8-BitProgrammable Backlight CodeSelectable Analog ALS Input with 128Programmable Gain-Setting Resistors or PWMALS Input With Internal Low-Pass FilterPWM Input for Content Adjustable BrightnessControlFive Low-Voltage Current Sinks for Indicator LEDsIntegrated Charge Pump for Improved Efficiencyand VINOperating RangeInternal Pattern Generation EngineFully Configurable LED Grouping and ControlFour Programmable Overvoltage ProtectionThresholds (16 V, 24 V, 32 V, and 40 V)Programmable 500-kHz and 1-MHz SwitchingFrequency27-mm2Total Solution SizeDrives Two Parallel High-Voltage LED Strings forDisplay and Keypad LightingHigh-Voltage Strings Capable of up to 40-VOutput Voltage and up to 90% EfficiencyUp to 30 mA per Current Sink (Both Backlight andIndicator)14-Bit Equivalent Exponential Dimming With 8-BitProgrammable Backlight CodeSelectable Analog ALS Input with 128Programmable Gain-Setting Resistors or PWMALS Input With Internal Low-Pass FilterPWM Input for Content Adjustable BrightnessControlFive Low-Voltage Current Sinks for Indicator LEDsIntegrated Charge Pump for Improved Efficiencyand VINOperating RangeInternal Pattern Generation EngineFully Configurable LED Grouping and ControlFour Programmable Overvoltage ProtectionThresholds (16 V, 24 V, 32 V, and 40 V)Programmable 500-kHz and 1-MHz SwitchingFrequency27-mm2Total Solution Size
Description
AI
The LM3533 is a complete power source for backlight, keypad, and indicator LEDs in smartphone handsets. The high-voltage inductive boost converter provides the power for two series LED strings for display backlight and keypad functions (HVLED1 and HVLED2). The integrated charge pump provides the bias for the five low-voltage indicator LED current sinks (LVLED1 to LVLED5). All low-voltage current sinks can have a programmable pattern modulated onto their output current for a wide variety of blinking patterns.
Additional features include a pulse width modulation (PWM) control input for content adjustable backlight control (CABC), and an ambient light sensor interface (ALS) with an internal 8-bit ADC to provide automatic current adjustment based upon ambient light conditions. Both the PWM and ALS inputs can be used to control any high- or low-voltage current sink.
The LM3533 is fully programmable via an I2C-compatible interface. The device is available in a 20-pin DSBGA and operates over a 2.7-V to 5.5-V input voltage range and a −40°C to +85°C temperature range.
The LM3533 is a complete power source for backlight, keypad, and indicator LEDs in smartphone handsets. The high-voltage inductive boost converter provides the power for two series LED strings for display backlight and keypad functions (HVLED1 and HVLED2). The integrated charge pump provides the bias for the five low-voltage indicator LED current sinks (LVLED1 to LVLED5). All low-voltage current sinks can have a programmable pattern modulated onto their output current for a wide variety of blinking patterns.
Additional features include a pulse width modulation (PWM) control input for content adjustable backlight control (CABC), and an ambient light sensor interface (ALS) with an internal 8-bit ADC to provide automatic current adjustment based upon ambient light conditions. Both the PWM and ALS inputs can be used to control any high- or low-voltage current sink.
The LM3533 is fully programmable via an I2C-compatible interface. The device is available in a 20-pin DSBGA and operates over a 2.7-V to 5.5-V input voltage range and a −40°C to +85°C temperature range.
