LT3474/LT3474-1

3

3474fd

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.

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 LT3474E and LT3474E-1 are guaranteed to meet performance

specifications from 0°C to 70°C. Specifications over the –40°C to 85°C

The

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

Reference Voltage Line Regulation

0.01

%/V

Reference Voltage Load Regulation

0.0002

%/μA

l

20

400

nA

Switching Frequency

l

470

450

500

530

540

kHz

kHz

Maximum Duty Cycle

l

90

95

76

98

%

%

%

Foldback Frequency

70

kHz

SHDN Threshold (to Switch)

2.6

2.65

2.7

V

SHDN Pin Current (Note 5)

8.3

10.3

12.3

μA

PWM Threshold

0.4

0.9

1.2

V

0.8

V

100

μA

100

μA

1.5

μA/mA

1

V/mA

2A/V

1.9

V

l

0.01

1

μA

OUT Pin Clamp Voltage (LT3474)

13.2

13.8

14.5

V

OUT Pin Current in PWM Mode

l

0.1

10

μA

Switch Current Limit (Note 6)

–40°C to 85°C

LT3474I, LT3474I-1 at 125°C

l

1.6

1.5

2.1

3.2

3.2

A

A

380

500

mV

Boost Pin Current

30

50

mA

Switch Leakage Current

0.01

1

μA

Minimum Boost Voltage (Note 7)

1.9

2.5

V

Boost Diode Forward Voltage

600

mV

operating temperature range are assured by design, characterization and

correlation with statistical process controls. The LT3474I and LT3474I-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.

Note 7: This is the minimum voltage across the boost capacitor needed to

guarantee full saturation of the internal power switch.