Line Card

ADP5520

 2009-11-09

【Basic Info】

【Product Feature】

* Efficient asynchronous boost converter for driving up to 6 white LEDs
* 2.7 V to 5.5 V input voltage range
* 128 programmable backlight LED current levels (30 mA maximum)
* Ambient light sensing with autonomous backlight adjustment
* Programmable backlight fade-in/fade-out times
* Programmable backlight dim and off times
* 8 configurable GPIO pins (input, output, up to 4 × 4 keypad)
* Up to 3 auxiliary LED current sinks (1 dedicated, 2 configurable)
* 64 programmable auxiliary LED current levels (14 mA maximum)
* Programmable auxiliary LED fade-in/fade-out times
* Programmable auxiliary LED on and off times (allows blinking)
* 2.7 V to 5.5 V input voltage range
* Temperature range −40°C to +85°C
* 4.0 mm × 4.0 mm, 24-lead LFCSP package
* Standby Current ─ 45uA
* LED #: 6
* 128 programmable backlight LED current levels (30 mA maximum)
* Up to 3 auxiliary LED current sinks (1 dedicated, 2 configurable)
* 64 programmable auxiliary LED current levels (14 mA maximum)
* I2C-compatible serial interface
* 8 configurable GPIO pins (input, output, up to 4 × 4 keypad)

【Application】

Display backlight driver for phones that require slider or flip keypad functions with single or multiple LED indicators

【Overview】

The single-chip ADP5520 lighting management system enables a 20-percent reduction in battery power consumption through the use of an “intelligent” lighting-control that automatically detects ambient light levels and adjusts backlight brightness according to changing lighting environments. An adaptive ambient light management feature adjusts too-bright or washed-out screens autonomously according to configurable lighting profiles. This reduces current-drain and extends battery life by minimizing the processor involvement in backlight monitoring. In addition, the ADP5520 can assume control of key-scan and general-purpose I/O sub-system functions from the processor, further reducing system power consumption and increasing available processor bandwidth.

Using this highly integrated lighting management system, designers of “flip” or slider form factor phones can reduce the number of control lines running across the hinge of a phone from 53 lines down to 14. This brings significant cost and reliability benefits to flip phones or slider phones in which the backlighting system is located alongside the LCD display. In a typical mobile handset application, the ADP5520 integrates the keypad controls, lighting sensor, LED indicators, and backlight LED supply on a single chip, and also features programmable profiles with minimum software overhead to control LED backlight intensity, on/off timing, fade algorithm cubic (or square law), and dimming timers.