Backlight Driver with I/O Expander

The ADP5520 is a versatile single-chip, white LED backlight driver with a user configurable I/O expander. This device fits handset applications where the flip or slider section of the phone requires backlighting, I/O signaling and detecting, auxiliary LED lighting, and keypad functions. By incorporating an I2C-compatible serial interface and a single line interrupt, the ADP5520 significantly reduces the total number of lines required to interface with the baseband processor across the hinge flex.

The ADP5520 can detect ambient light levels and adjust the backlight brightness accordingly, resulting in extended battery operation.

Once configured, the ADP5520 is capable of controlling the flip/slider backlight intensity, on/off timing, dimming, and fading without the intervention of the main processor, which results in valuable battery power saving.

Applications

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

* 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)

* I2C-compatible serial interface

* Interrupt line for signaling an external processor (INT)

* Hard reset (RST)

* Current limit protection

* Thermal overload protection

* Available in small 4.0 mm × 4.0 mm, 24-lead LFCSP package