LT3475/LT3475-1

3

3475fb

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.

Note 2: This IC includes overtemperature protection that is intended

to protect the device during momentary overload conditions. Junction

temperature will exceed 125°C when overtemperature protection is active.

Continuous operation above the specified maximum operating junction

temperature may impair device reliability.

Note 3: The LT3475E and LT3475E-1 are guaranteed to meet performance

specifications from 0°C to 85°C. Specifications over the –40°C to 85°C

operating temperature range are assured by design, characterization and

correlation with statistical process controls. The LT3475I and LT3475I-1

are guaranteed to meet performance specifications over the –40°C to

125°C operating temperature range.

Note 4: Current flows out of pin.

Note 5: Current flows into pin.

Note 6: Current limit is guaranteed by design and/or correlation to static

test. Slope compensation reduces current limit at higher duty cycles.

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

LED Pin Current

LT3475E/LT3475E-1 0°C to 85°C

●

●

0.97

0.94

0.336

0.325

0.31

1.00

0.350

1.03

1.04

0.364

0.375

0.385

A

A

A

A

A

REF Voltage

●

1.22

1.25

1.27

V

Reference Voltage Line Regulation

0.05

%/V

Reference Voltage Load Regulation

0.0002

%/μA

●

40

400

nA

Switching Frequency

●

530

600

640

kHz

Maximum Duty Cycle

●

90

95

80

98

%

%

%

Switching Phase

150

180

210

Deg

Foldback Frequency

80

kHz

SHDN Threshold (to Switch)

2.5

2.6

2.74

V

SHDN Pin Current (Note 5)

79

11

μA

PWM Threshold

0.3

0.8

1.2

V

0.8

V

50

μA

50

μA

500

V/A

1

mA/μA

2.6

A/V

1.8

V

●

10

400

nA

OUT Pin Clamp Voltage (LT3475)

13.5

14

14.5

V

OUT Pin Current in PWM Mode

●

25

50

μA

Switch Current Limit (Note 6)

2.3

2.7

3.2

A

350

500

mV

BOOST Pin Current

25

40

mA

Switch Leakage Current

0.1

10

μA

Minimum Boost Voltage Above SW

1.8

2.5

V

ELECTRICAL CHARACTERISTICS