Features

• Multimode Charge Pump Provides Up to 91% Efficiency
• Slew Limited Switching Reduces Conducted and Radiated Noise (EMI)
• Up to 250mA Total Output Current
• Nine 28mA Universal Current Sources with 64-Step Linear Brightness Control
• Independent On/Off, Brightness Level, Blinking and Gradation Control for Each Current Source Using 2-Wire I2C Interface
• Internal Current Reference
• Configurable ENU Pin for Asynchronous LED On/Off Control
• Low Noise Charge Pump Operates in 1x, 1.5x or 2x Mode for Optimal Efficiency*
• Automatic or Forced Mode Switching
• Internal Soft-Start Limits Inrush Current
• Short-Circuit/Thermal Protection
• 3mm × 3mm 20-Lead QFN Plastic Package

Typical Application

Description

The LTC3219 is a highly integrated multidisplay LED driver. The device contains a high efficiency, low noise charge pump to provide power to nine universal LED current sources. The LTC3219 requires only five small ceramic capacitors to form a complete LED power supply and current controller.

The maximum display currents are set by an internal precision current reference. Independent dimming, On/Off, blinking and gradation control for all current sources is achieved via the I2C serial interface. 6-bit linear DACs are available for adjusting brightness levels for each universal LED current source.

The LTC3219 charge pump optimizes efficiency based on the voltage across the LED current sources. The device powers up in 1x mode and will automatically switch to boost mode whenever any enabled LED current source begins to enter dropout. The first dropout switches the IC into 1.5x mode and a subsequent dropout switches the LTC3219 into 2x mode. The part resets to 1x mode whenever a data register is updated via the I2C port.