LT3597

1

3597f

TYPICAL APPLICATION

DESCRIPTION

60V Triple Step-Down

LED Driver

of achieving 10,000:1 digital PWM dimming at 100Hz with

fast NPN current sources driving up to 10 LEDs in each

channel. LED dimming can also be achieved via analog

control of the CTRL1-3 pin.

The step-down switching frequency is programmed be-

tween200kHzand1MHz.Thefrequencyisalsosynchroniz-

able to an external clock. The LT3597 provides maximum

LED brightness while adhering to manufacturers’ speci-

fications for thermal derating. The derate temperature is

programmedbyplacinganegativetemperaturecoefficient

(NTC) resistor on the master control pin.

optimal efficiency. Other features include: 2% LED cur-

rent matching between channels, open LED reporting,

shorted LED protection, programmable LED current, and

programmable temperature protection.

L

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

PWM is a trademark of Linear Technology Corporation. All other trademarks are the property of

their respective owners.

Triple Step-Down RGB Single Pixel LED Driver, 100mA Current

FEATURES

APPLICATIONS

n

Three 100mA Buck Regulators, Each Drives Up to

10 LEDs with Fast NPN Current Sources

n

Fast Current Sources for <1µs Pulse Widths

(10,000:1 True Color PWM™ Dimming at 100Hz)

n

LEDs Disconnected in Shutdown

n

n

6V to 60V Input Voltage Range

n

±2% LED Current Matching

n

External Resistor Sets LED Current for Each Channel

n

Internal Compensation and Soft-Start

n

Programmable Switching Frequency (200kHz to 1MHz)

n

Synchronizable to External Clock

n

Open LED Detection and Reporting

n

Shorted LED Pin Protection and Reporting

n

Programmable LED Thermal Derating

n

Programmable Temperature Protection

n

5mm

× 8mm Thermally Enhanced QFN Package

with a 0.6mm High Voltage Pin Spacing

n

LED Billboards and Signboards

n

Mono, Multi, Full-Color LED Displays

n

Large Screen Display LED Backlighting

n

Automotive, Industrial, and Medical Displays

10,000:1 PWM Dimming at 100Hz

3597 TA01a

LT3597

EN/UVLO

BOOST1

SW1

DA1

FB1

LED1

BIAS

FAULT

PWM1-3

CTRL1-3

SYNC

RT

BOOST2

SW2

DA2

FB2

LED2

BOOST3

SW3

DA3

FB3

LED3

CTRLM

LT3597

9.1k

R

100k

97k

91k

270k

3.3µF

0.1µF

10µF

100µH

0.1µF

3.3µF

100µH

9.1k

97k

0.1µF

3.3µF

100µH

9.1k

97k

100k

10k

82.5k

49.9k

10µF

5V

48V

33.2k

(1MHz)

GND

20k

20k

20k

3

3

G

B

50mA/DIV

PWM

2V/DIV

3597 TA01b

200ns/DIV