3

LT1372/LT1377

SYMBOL

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

Maximum Switch Duty Cycle

q

85

95

%

Switch Current Limit Blanking Time

130

260

ns

BV

Output Switch Breakdown Voltage

LT1372/LT1377

q

35

47

V

LT1372HV

0

q

42

47

V

– 40

40

V

Output Switch “On” Resistance

q

0.5

0.8

Ω

Switch Current Limit

Duty Cycle = 50%

q

1.5

1.9

2.7

A

Duty Cycle = 80% (Note 2)

q

1.3

1.7

2.5

A

Supply Current Increase During Switch On-Time

15

25

mA/A

Control Voltage to Switch Current

2A/V

Transconductance

Minimum Input Voltage

q

2.4

2.7

V

Supply Current

2.7V

q

4

5.5

mA

Shutdown Supply Current

2.7V

0

q

12

30

µA

– 40

50

µA

Shutdown Threshold

2.7V

q

0.6

1.3

2

V

Shutdown Delay

q

512

25

µs

S/S Pin Input Current

0V

q

–10

15

µA

Synchronization Frequency Range

LT1372

q

600

800

kHz

LT1377

q

1.2

1.6

MHz

Switch Saturation Voltage

vs Switch Current

TEMPERATURE (

°C)

–50

1.8

2.0

2.2

2.4

2.6

050

100

150

LT1372 • G03

2.8

3.0

–25

25

75

125

Minimum Input Voltage

vs Temperature

DUTY CYCLE (%)

0

1.0

2.0

3.0

0.5

1.5

2.5

20

40

60

80

LT1372 • G02

100

10

0

30

50

70

90

25

°C AND

125

°C

–55

°C

Switch Current Limit

vs Duty Cycle

SWITCH CURRENT (A)

0

0.6

0.8

1.0

1.6

LT1372 • G01

0.4

0.2

0.5

0.7

0.9

0.3

0.1

0

0.4

0.8

1.2

2.0

1.4

0.2

0.6

1.0

1.8

100

°C

150

°C

25

°C

–55

°C

Note 1: Absolute Maximum Ratings are those values beyond which the life

of the device may be impaired.

ELECTRICAL CHARACTERISTICS

Note 2: For duty cycles (DC) between 50% and 90%, minimum