Linear Technology LT3595EUHH, LT3595 Datasheet

LT3595

1

3595f

, 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.

TYPICAL APPLICATION

FEATURES

APPLICATIONS

DESCRIPTION

16 Channel

Buck Mode LED Driver

The LT®3595 is a high performance LED Driver designed
to drive sixteen independent channels of up to 10 LEDs
at currents up to 50mA. Series connection of the LEDs
provides identical LED currents resulting in uniform bright­ness. Power switches, Schottky diodes, and compensation
components are all internal, providing a small converter
footprint and lower component cost. The high 2MHz
switching frequency permits the use of tiny, low profi le
inductors and capacitors. A fi xed frequency, current mode
architecture results in stable operation over a wide range
of supply and output voltage.

A single external resistor sets the LED current for all sixteen
channels, and dimming is then controlled for each channel
by pulse width modulating the individual PWM pins. Rela­tive current matching among the sixteen drivers is 8% and
the PWM dimming range is 5000:1. The part is available
in a 5mm × 9mm × 0.75mm 56-pin QFN package.

16-Channel LED Driver (Three LEDs per Channel), 20mA Current

■

4.5V to 45V Input Supply Range

■

Up to 50mA LED Current per Channel

■

100mA, 45V Internal Switches

■

8% Relative LED Current Match at 20mA

■

16 Independent LED Channels

■

5000:1 True Color PWMTM Dimming Range

■

LEDs Disconnected in Shutdown

■

Internal Schottky Diodes

■

Low Quiescent Current

■

2MHz Switching Frequency

■

R

SET

Pin Sets Master LED Current

■

Typical Effi ciency: 92%

■

Open LED Detection and Thermal Protection

■

56-Pin 5mm × 9mm × 0.75mm QFN Package

■

LED Video Billboards

■

LCD Televisions

■

Stadium and Advertising Displays

5000:1 PWM

Dimming at 100Hz

V

IN

15V TO

45V

LED

BRIGHTNESS

CONTROL

V

CC

3V TO

5.5V

V

CC

0.47μF 0.47μF 0.47μF 0.47μF 0.47μF 0.47μF 0.47μF 0.47μF

0.47

μF

10

μF

10

μF

100k

75.0k

0.47μF 0.47μF 0.47μF 0.47μF 0.47μF 0.47μF 0.47μF

3595 TA01

OPENLED
PWM1
PWM2
PWM3
PWM4
PWM5
PWM6
PWM7
PWM8

V

CC

PWM9
PWM10
PWM11
PWM12
PWM13
PWM14
PWM15
PWM16

GND
R

SET

L1 SW1 SW2 L4SW3 SW7L3 SW4 L5 L6SW5 SW6L2 L7 SW8 L8

L16 SW16 SW15 V

IN

L13SW14 VINSW10L14 SW13 L12 L11SW12 SW11L15 L10 SW9 L9

100μH

100

μH

100

μH

100μH100

μH

100μH

100

μH

100μH

100

μH

100

μH

100

μH

100μH100

μH

100μH

100

μH

100μH

SHDN

LT3595

LED
BRIGHT­NESS
CONTROL

400ns/DIV

I

LED

10mA/DIV

I

SW

20mA/DIV

V

PWM

5V/DIV

3595 TA01

b

V

IN

= 15V

3 LEDS AT 20mA

T = 10ms
T

ON

= 2μs

LT3595

2

3595f

PIN CONFIGURATIONABSOLUTE MAXIMUM RATINGS

Input Voltage (VIN) ....................................................45V

L1-16 Voltage ...........................................................45V

Supply Voltage (V

CC

) ..................................................6V

R

SET

, ⎯O⎯P⎯E⎯N⎯L⎯E⎯D , PWM1-16, ⎯S⎯H⎯D⎯N Voltage ...............6V

Operating Junction Temperature Range

(Note 2) ...............................................–40°C to 85°C

Maximum Junction Temperature .......................... 125°C

Storage Temperature Range ...................–65°C to 125°C

(Note 1)

19 20 21 22

TOP VIEW

57

UHH PACKAGE

56-LEAD (5mm × 9mm) PLASTIC QFN

23 24 25 26 27 28

56 55 54 53 52 51 50 49 48 47

39

40

41

42

43

44

45

46

8

7

6

5

4

3

2

1L16

SW16

L15

SW15

V

IN

SW14

L14

SW13

L13

L12

SW12

L11

SW11

V

IN

SW10

L10

SW9

L9

L1

SW1

L2

SW2

NC

SW3

L3

SW4

L4

L5

SW5

L6

SW6

NC

SW7

L7

SW8

L8

PWM16

PWM15

PWM14

PWM13

VCCR

SET

PWM4

PWM3

PWM2

PWM1

38

37

36

35

34

33

32

31

30

29

9

10

11

12

13

14

15

16

17

18

PWM9

PWM10

PWM11

PWM12

OPENLED

SHDN

PWM5

PWM6

PWM7

PWM8

T

JMAX

= 125°C, θJA = 31°C/W, θJC = 0.5°C/W

EXPOSED PAD (PIN 57) IS GND, MUST BE SOLDERED TO PCB

ORDER INFORMATION

LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE

LT3595EUHH#PBF LT3595EUHH#TRPBF 3595 56-Lead (5mm × 9mm) Plastic QFN –40°C to 85°C

Consult LTC Marketing for parts specifi ed with wider operating temperature ranges.
Consult LTC Marketing for information on non-standard lead based fi nish parts.

For more information on lead free part marking, go to: http://www.linear.com/leadfree/
For more information on tape and reel specifi cations, go to: http://www.linear.com/tapeandreel/

LT3595

3

3595f

ELECTRICAL CHARACTERISTICS

Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.

PARAMETER CONDITIONS MIN TYP MAX UNITS

V

IN

Operating Voltage

4.5 V

V

CC

Operating Voltage

3 5.5 V

V

CC

Input Under Voltage Lockout

2.6 2.9 V

I

VIN

Quiescent Current ON, No Switching VIN = 45V 0.25 mA

I

VIN

Quiescent Current in Shutdown VIN = 45V, ⎯S⎯H⎯D⎯N = 0V 15 40 μA

I

VCC

Quiescent Current ON, No Switching VCC = 3.3V 17 mA

I

VCC

Quiescent Current in Shutdown VCC = 3.3V, ⎯S⎯H⎯D⎯N = 0V 3 10 μA

I

L1-16

Output Current Accuracy R

SET

= 75.0kΩ 18.4 20 21.6 mA

Switching Frequency 1.622.4MHz

Maximum Duty Cycle

●

78 83 %

Switch Current Limit

●

90 120 150 mA

Switch V

CESAT

ISW1-16 = 50mA 450 mV

Switch Leakage Current VSW1-16 = 45V 0.1 6 μA

Schottky Forward Drop I

SCHOTTKY

= 50mA 0.8 V

Schottky Leakage Current V

IN

= 45V, V

SW1-16

= 0.7V, ⎯S⎯H⎯D⎯N = 0V 0.1 4 μA

⎯S⎯H⎯D⎯

N, PWM1-16 Input Low Voltage 0.4 V

⎯S⎯H⎯D⎯

N, PWM1-16 Input High Voltage 1.6 V

⎯S⎯H⎯D⎯

N Pin Bias Current

⎯S⎯H⎯D⎯

N = 3.3V 35 μA

PWM1-16 Pin Bias Current PWM1-16 = 3.3V 0.1 1 μA

⎯O⎯P⎯E⎯N⎯L⎯E⎯

D Pin Voltage VCC = 3.3V, I

⎯O⎯P⎯E⎯N⎯L⎯E⎯

D

= 200μA 0.12 V

⎯O⎯P⎯E⎯N⎯L⎯E⎯

D Pin Input Leakage Current

⎯O⎯P⎯E⎯N⎯L⎯E⎯

D = 3.3V 0.1 1 μA

The ● denotes the specifi cations which apply over the full operating
temperature range, otherwise specifi cations are at T

A

= 25°C, VIN = 45V, VCC = 3.3V, PWM = ⎯S⎯H⎯D⎯N = ⎯O⎯P⎯E⎯N⎯L⎯E⎯D = 3.3V, R

SET

= 75kΩ,

GND = 0V, unless otherwise noted.

Note 2: The LT3595 is guaranteed to meet performance specifi cations

from 0°C to 85°C junction temperature. Specifi cations over the – 40°C
to 85°C operating junction temperature range are assured by design,
characterization and correlation with statistical process controls.

LT3595

4

3595f

R

SET

RESISTANCE (kΩ)

25

LED CURRENT (mA)

30

50

40

60

50 150

20

10

0

75 100 125

3595 G05

DUTY CYCLE (%)

0.01

LED CURRENT (mA)

1

10

100

0.1

0.01

0.001

0.1

1

10

100

3595 G04

VIN = 45V
10 LEDS AT 20mA
PWM FREQUENCY = 100Hz

TYPICAL PERFORMANCE CHARACTERISTICS

Switching Waveforms

PWM Dimming Waveforms
(1000:1)

LED Current vs PWM Duty Cycle
Wide Dimming Range (5000:1)

LED Current vs R

SET

Resistance

VIN Quiescent Current

VCC Quiescent Current

⎯S⎯H⎯D⎯

N Pin Bias Current

PWM Dimming Waveforms
(10:1)

VIN (V)

0

V

IN

CURRENT (mA)

1.2

1.6

2.0

40

0.8

0.4

0

10

20

30

50

3595 G06

T = 25°C

T = 125°C

T = – 40°C

400ns/DIV

10 LEDS

V

SW1

50V/DIV

10 LEDS

I

L1

50mA/DIV

5 LEDS

V

SW2

50V/DIV

5 LEDS

I

L2

50mA/DIV

3595 G01

V

IN

= 45V

I

LED

= 20mA

2μs/DIV

I

LED

20mA/DIV

I

L

20mA/DIV

PWM

5V/DIV

3595 G02

V

IN

= 40V

10 LEDS AT 20mA

PWM FREQUENCY = 100H

z

TON = 10μs

2ms/DIV

I

LED

20mA/DIV

I

L

20mA/DIV

PWM

5V/DIV

3595 G03

V

IN

= 40V

10 LEDS AT 20mA

PWM FREQUENCY = 100H

z

TON = 1ms

V

CC

(V)

0

0

V

CC

CURRENT (mA)

2

6

8

10

20

14

2

4

5

4

16

18

12

1

3

6

7

3595 F07

T = 125°C

T = –40°C

T = 25°C

VCC = 3.3V

0

0

20

40

60

80

100

1

234

56

3595 F08

T = 125°C

T = –40°C

I

SHDN

(μA)

T = 25°C

V

SHDN

(V)

LT3595

5

3595f

Current Limit vs Temperature

TYPICAL PERFORMANCE CHARACTERISTICS

Switching Frequency
vs Temperature

Schottky Leakage Current
vs Temperature

Switch Saturation Voltage
(V

CESAT

)

Schottky Forward Voltage Drop

Transient Response

⎯O⎯P⎯E⎯N⎯L⎯E⎯

D Waveforms

TEMPERATURE (°C)

–50

130

140

150

25 75

120

110

–25 0

50 100 125

100

90

CURRENT LIMIT (mA)

3595 G09

TEMPERATURE (°C)

–50

2.0

2.2

2.1

2.3

2.4

25 75

1.9

1.8

–25 0

50 100 125

1.7

1.6

SWITCHING FREQUENCY (MHz)

3595 G10

TEMPERATURE (°C)

–50

0.8

1.0

1.4

25 75

0.6

0.4

–25 0

50 100 125

0.2

0

1.2

SCHOTTKY LEAKAGE CURRENT (μA)

3595 G11

VIN = 45V

VIN = 24V

VIN = 4.5V

SWITCH CURRENT (mA)

0

500

600

700

80

400

300

20 40 60 100

200

100

0

SWITCH SATURATION VOLTAGE (mV)

T = 125°C

T = –40°C

T = 25°C

SCHOTTKY FORWARD DROP (V)

0

SCHOTTKY FORWARD CURRENT (mA)

60

80

100

0.8

40

20

0

0.2

0.4

0.6

1

3595 G13

T = 125°C

T = – 40°C

T = 25°C

100μs/DIV

V

SW

50V/DIV

I

SW

50mA/DIV

I

LED

20mA/DIV

3595 G1

4

V

IN

= 45V

10 LEDS AT 20mA

V

SHDN

5V/DIV

20μs/DIV

V

SW

CH 1

50V/DIV

I

LED

CH 2

20mA/DIV

I

LED

CH 1

20mA/DIV

3595 G1

5

OPENLED

5V/DIV

V

IN

= 45V

10 LEDS AT 20mA