LT1940

2

1940i

BOOST Pin Voltage .................................................. 35V

BOOST Pin Above SW Pin ....................................... 25V

PG Pin Voltage ......................................................... 25V

SHDN, FB Pins ........................................................... 6V

Maximum Junction Temperature .......................... 125

°C

Operating Temperature Range (Note 2) ...–40

°C to 85°C

Storage Temperature Range ..................–65

°C to 150°C

Lead Temperature (Soldering, 10 sec).................. 300

°C

ORDER PART

NUMBER

UNDERSIDE METAL MUST BE

SOLDERED TO GROUND

LT1940EFE

ABSOLUTE

AXI U

RATI GS

PACKAGE/ORDER I FOR ATIO

(Note 1)

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

Minimum Operating Voltage

q

3.4

3.6

V

Quiescent Current

Not Switching

3.8

4.8

mA

Shutdown Current

30

45

µA

Feedback Voltage

1.230

1.250

1.270

V

0

°C to 70°C

q

1.225

1.250

1.270

V

–40

°C to 85°C

q

1.215

1.250

1.270

V

FB Pin Bias Current

q

240

1200

nA

Reference Line Regulation

0.005

%/V

Error Amp GM

330

uMhos

Error Amp Voltage Gain

180

42

µA

60

µA

2.4

A/V

0.75

V

1.8

V

Switching Frequency

1

1.1

1.25

MHz

q

0.95

1.1

1.35

MHz

Switching Phase

150

180

210

Deg

Maximum Duty Cycle

q

78

88

%

Frequency Shift Threshold on FB

0.5

V

Foldback Frequency

150

kHz

Switch Current Limit

Note 3

1.8

2.4

3.2

A

210

320

mV

Switch Leakage Current

10

µA

Consult LTC Marketing for parts specified with wider operating temperature ranges.

FE PACKAGE

16-LEAD PLASTIC TSSOP

1

2

3

4

5

6

7

8

TOP VIEW

16

15

14

13

12

11

10

9

BOOST1

SW1

SW2

BOOST2

FB1

PG1

RUN/SS1

RUN/SS2

PG2

FB2