3

LT1738

1738fa

other pins open unless otherwise noted.

SYMBOL

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

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

life of a device may be impaired.

Note 2: Supply current specification includes loads on each gate as in

Figure 1a. Actual supply currents vary with operating frequency, operating

voltages, V5 load, slew rates and type of external FET.

Note 3: The LT1738E is guaranteed to meet performance specifications

from 0

°C to 70°C. Specifications from –40°C to 125°C are assured by

Oscillator and Sync

Max Switch Frequency

250

kHz

Synchronization Frequency Range

Oscillator Frequency = 250kHz

290

kHz

SYNC Pin Input Threshold

q

0.7

1.4

2

SYNC Pin Input Resistance

40

k

Ω

Gate Drive

Maximum Switch Duty Cycle

q

90

93.5

%

Osc Frequency = 25kHz

Gate On Voltage

10

10.4

10.7

V

7.6

7.9

8.1

V

Gate Off Voltage

0.2

0.35

V

Max Gate Source Current

0.3

A

Max Gate Sink Current

0.3

A

Gate Drive Undervoltage Lockout (Note 5)

7.3

7.5

V

Current Sense

Switch Current Limit Blanking Time

100

ns

Sense Voltage Shutdown Voltage

q

86

103

120

mV

Sense Voltage Fault Threshold

220

300

mV

Slew Control for the Following Slew Tests See Test Circuit in Figure 1b

Output Voltage Slew Rising Edge

26

V/

µs

Output Voltage Slew Falling Edge

19

V/

µs

Output Current Slew Rising Edge (CS pin V)

2.1

V/

µs

Output Current Slew Falling Edge (CS pin V)

2.1

V/

µs

Supply and Protection

Minimum Input Voltage (Note 4)

q

2.55

3.6

V

Supply Current (Note 3)

q

12

40

mA

35

55

mA

Shutdown Turn-On Threshold

q

1.31

1.39

1.48

V

Shutdown Turn-On Voltage Hysteresis

q

50

110

180

mV

Shutdown Input Current Hysteresis

q

10

24

35

µA

V5

5V Reference Voltage

6.5V

4.85

5

5.20

V

6.5V

4.80

5

5.15

V

5V Reference Short-Circuit Current

10

mA

–10

mA

design, characterization and correlation with statistical process

controls.The LT1738I is guaranteed and tested to meet performance

specifications from – 40

°C to 125°C.

Note 4: Output gate drive is enabled at this voltage. The GCL voltage will

also determine driver activity.