LTC3219

1

3219fa

TYPICAL APPLICATION

FEATURES

APPLICATIONS

DESCRIPTION

250mA Universal

Nine Channel LED Driver

The LTC

driver. The device contains a high efficiency, low noise

charge pump to provide power to nine universal LED

current sources. The LTC3219 requires only five small

ceramic capacitors to form a complete LED power supply

and current controller.

The maximum display currents are set by an internal pre-

cision current reference. Independent dimming, On/Off,

blinking and gradation control for all current sources is

available for adjusting brightness levels for each universal

LED current source.

The LTC3219 charge pump optimizes 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 LTC3219 into 2x mode. The part resets to 1x mode

■

Multimode Charge Pump Provides Up to 91%

Efficiency

■

Slew Limited Switching Reduces Conducted and

Radiated Noise (EMI)

■

Up to 250mA Total Output Current

■

Nine 28mA Universal Current Sources with 64-Step

Linear Brightness Control

■

Independent On/Off, Brightness Level, Blinking and

Gradation Control for Each Current Source Using

■

Internal Current Reference

■

Configurable ENU Pin for Asynchronous LED On/Off

Control

■

Low Noise Charge Pump Operates in 1x, 1.5x or 2x

Mode for Optimal Efficiency*

■

Automatic or Forced Mode Switching

■

Internal Soft-Start Limits Inrush Current

■

Short-Circuit/Thermal Protection

■

3mm

× 3mm 20-Lead QFN Plastic Package

■

Video Phones with QVGA+ Displays

, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.

All other trademarks are the property of their respective owners.

*Protected by U.S. Patents, including 6411531.

C3

1μF

C1P C1M

GND

C2

1μF

C2P

LTC3219

C2M

CPO

ULED1-9

3219 TA01a

29

MAIN

SUB

RGB

SCL/SDA

C1

2.2μF

0.1μF

C4

2.2μF

ENABLE DISABLE

ENU

4-LED Main, 2-LED Sub and RGB