3

LT1248

2

Note 2: Multiplier Gain Constant: K =

ELECTRICAL C

C

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

of a device may be impaired

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

Current Amplifier

Current Amp Short-Circuit Current

q

514

30

mA

q

– 0.3

1

V

Reference

Reference Output Voltage

7.39

7.50

7.60

V

5

mV

q

–20

5

20

mV

q

12

28

50

mA

Load, Line, Temperature

q

7.32

7.5

7.68

V

Current Limit

q

–15

15

mV

q

– 50

– 100

µA

400

ns

Multiplier

Multiplier Output Current

35

µA

Multiplier Output Current Offset

q

– 0.05

– 0.5

µA

Multiplier Maximum Output Current

q

– 286

– 260

– 235

µA

Multiplier Gain Constant (Note 2)

0.035

15

32

50

k

Ω

Oscillator

Oscillator Frequency

q

85

100

115

kHz

q

58

68

78

kHz

4.35

4.7

5.0

V

1.25

1.4

1.55

V

Synchronization Pulse Threshold on EN/SYNC Pin

Pulse Low = 3.5V, High = 7V, Width > 200ns

4.5

5.6

6.5

V

Synchronization Frequency Range

q

1.2

1.6

Overvoltage Comparator

q

1.04

1.05

1.06

Hysteresis

0.35

V

OVP Bias Current

OVP = 7.5V

q

– 50

– 250

nA

OVP Propagation Delay

100

ns

Gate Driver

Max GTDR Output Voltage

q

12

15

17.5

V

GTDR Output High

– 200mA Load, 11.5V

q

V

GTDR Output Low (Device Unpowered)

q

0.9

1.5

V

GTDR Output Low (Device Active)

200mA Load (Sinking)

q

0.5

1

V

10mA Load

q

0.2

0.4

V

Peak GTDR Current

10nF from GTDR to GND

2

A

GTDR Rise and Fall Time

1nF from GTDR to GND

25

ns

GTDR Max Duty Cycle

90

96

%