United States Patents: 6,504,422, 6,794,926

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1

POWER MANAGEMENT

SC606

Low Noise Smart LED

Driver with Serial Interface

Description

August 31, 2006

Applications

Features

The SC606 is a very high efficiency charge pump white/color LED

Li-Ion battery applications. The LED current is regulated to a value

LED outputs are current-matched for consistent LED brightness.

Up to 6 LEDs are controlled in three zones for brightness control in

multiple displays. The 6 LED outputs are divided into 3 pairs of

LEDs. Each pair has current that is programmable independent of

the other pairs. Any combination of LEDs may be turned on using

the serial interface. The SC606 also has a float detect feature

that disables any current driver during normal operation when an

open-load condition is detected.

Patented low noise switching circuitry and constant output current

allow the use of extremely small input and output capacitors.

Very High Efficiency Over 90% of Battery Life

Current Regulation for 6 LEDs

Current Matching Tolerance of +/- 3.5% from LED to LED

Current Accuracy to +/- 6.5% of Specified Value

Current Range per LED [0.5mA - 32mA]

High Available Total LED Current = 6 I

Soft-Start /In-rush Current Limiting

Short Circuit /Thermal Protection

MLP-16 [4x4] Package

1.33MHz and 250kHz Programmable Fixed Frequency

Separate Brightness Zones for Multiple Displays

Three Charge Pump Modes of Operation: 1x, 1.5x and 2x

Open LED Output Protection

Cellular Phones

LED Backlighting

PDA Power Supplies

Portable Devices

Electronic Books

Wireless Web Appliances

Typical Application Circuit

C3

1µF

C4

1µF

VBAT

1

2

3

4

9

10

SCL

SDA

EN

C2

1µF

C2-

C2+

GND

ILEDC2

ILEDA1

SDA

SCL

EN

D1

SC606

11

12

C1

1µF

D6

D5

D4

D3

D2

Patent Pending