LTC3209

peculiarity

• Multi-mode charge pump provides up to 94% efficiency (1x, 1.5x, 2x)
• Up to 600mA total output current
• LTC3209-1: 8 current sources can be used as -
  Six 25mA primary (MAIN) displays, one 400mA camera (CAM) display, and one 15mA secondary (AUX) display
• LTC3209-2: 8 current sources can be used as -
  Five 25mA main displays, two 200mA camera displays, and one 15mA auxiliary display
• LED on/off and brightness levels can be 2-wire I²C^TMinterface to set
• Automatic charge pump mode switching or fixed mode for generating power
• Low noise constant frequency operation*
• An internal soft-start feature limits inrush current during start-up and mode switching
• Short circuit protection / thermal protection / LED open circuit or short circuit protection
• The main display has 256 brightness levels
• The camera display has 16 brightness levels
• The auxiliary display has 4 brightness levels
• 20-pin (4mm × 4mm) QFN package

• description

  LTC^®The 3209-1/LTC3209-2 are highly integrated multidisplay LED controllers. These devices include a high-efficiency, low-noise charge pump to power the primary, camera, and auxiliary LED displays. The LTC3209-1/LTC3209-2 require only four small ceramic capacitors and one current setting resistor to form a complete LED power and current controller.

  The maximum current of the main / camera / auxiliary display is set with a single resistor. The current of each LED is controlled by a precise internal current source. Dimming and on/off control of all displays is via 2-wire I²C serial interface to implement. The primary display offers 256 brightness states, the camera display offers 16 brightness states, and the auxiliary display offers 4 brightness states.

  The charge pump optimizes efficiency based on the voltage across the LED current source. The device enters 1x mode after powering up and automatically switches to boost mode when either enabled main or camera LED current source begins to enter a dropout state. The first drop will switch the device to 1.5x mode, and the subsequent drop will switch the device to 2x mode. When a data bit passes through I²When the C port is updated, the device is reset to 1x mode. The devices are available in 4mm × 4mm 20-pin QFN packages

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  • Video / Cellular phones with QVGA+ displays