Programmable Current Backlight Driver

with Ambient Light Sensor Input

ADP5501

Rev. 0

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FEATURES

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)

Programmable backlight fade-in/fade-out times

Programmable backlight dim and off times

Ambient light sensing with autonomous backlight

adjustment

3 auxiliary LED current sinks

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)

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

APPLICATIONS

Display backlight driver with ambient light sensor input and

control and multiple LED indicator sinks

TYPICAL OPERATING CIRCUIT

1

PGND

21

VBAT

1µF

2.7V TO 5.5V

1µF

4.7µH

16

VDDIO

5

SCL

4

SDA

3

INT

15

RST

ADP5501

I/O RAIL

2

SW

22

BST

23

BL_SNK

20

CAP_OUT

13

LED2

6

NC

7

NC

8

NC

9

NC

10

NC

11

NC

12

LED1

14

LED0

3.3V

1µF

19

18

24

GND

GND

GND

VBAT

100nF

17

CMP_IN

RGB

Figure 1.

GENERAL DESCRIPTION

The ADP5501 is a versatile, single-chip, white LED backlight

driver with programmable ambient light sensor input and

programmable LED current. This device is designed for media-

compatible serial interface and a single line interrupt to

communicate with the host processor.

The ADP5501 can detect ambient light levels and adjust the

backlight brightness accordingly, resulting in extended battery life.

Once configured, the ADP5501 is capable of controlling the

display backlight intensity, on/off timing, dimming, and fading

without the intervention of the main processor, which translates

into valuable battery power savings. The three auxiliary LEDs

are also capable of fading and are timed on and off via register

programming.