The LTC3207/LTC3207-1 are highly integrated multi-display LED drivers. The device contains a high-efficiency, low-noise charge pump to provide power to 12 universal LED current sources and one camera LED current source. The LTC3207/LTC3207-1 require only five small ceramic capacitors to form a complete LED power supply and current controller. In addition there are two I2C addresses available.
The display currents are set by an internal precision current reference. Independent dimming, On/Off, blinking and gradation control for all universal 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 CAM current source has a 4-bit linear DAC to adjust brightness.
The LTC3207/LTC3207-1 charge pumps optimize 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 LTC3207/LTC3207-1 into 2x mode. The device resets to 1x mode whenever a data register is updated via the I2C port.
Feature
- Low Noise, Multi-Mode Charge Pump (1x, 1.5x, 2x) Provides Up to 91% Efficiency
- Slew Limited Switching Reduces Conducted and Radiated Noise (EMI)
- Up to 600mA Total Output Current
- Twelve 28mA Universal Current Sources with 64-Step Linear Brightness Control
- 425mA CAM LED Current Source with 16-Step Linear Brightness Control and 2-Second High Current Safety Timer
- Independent On/Off, Brightness Level, Blinking and Gradation Control for Each Current Source Using 2-Wire I2C Interface
- Internal Current Reference
- Two I2C Addresses are Available (LTC3207 00110110, LTC3207-1 00110100)
- Configurable ENU Pin for Asynchronous LED On/Off Control
- Automatic or Forced Mode Switching
- Internal Soft-Start Limits Inrush Current
- Short-Circuit/Thermal Protection
- 4mm × 4mm 24-Pin QFN Plastic Package
Applications
- Video Phones with QVGA+ Displays
(Picture: Pinout)
