LT1109

2

SYMBOL

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

Quiescent Current

Switch Off

q

320

550

µA

Minimum Start-Up Voltage

1.6

V

Input Voltage (N8, S8 Package)

q

3V

Comparative Trip Point Voltage

LT1109

q

1.20

1.25

1.30

V

Output Voltage

LT1109-5; 3V

q

4.75

5.00

5.25

V

LT1109-12; 3V

q

11.52

12.00

12.55

V

Comparator Hysteresis

LT1109

q

8

12.5

mV

Output Voltage Ripple

LT1109-5

q

25

50

mV

LT1109-12

q

60

120

mV

Oscillator Frequency

100

120

140

kHz

q

90

150

kHz

Switch ON Time

3.3

4.2

5.3

µs

q

3.0

5.5

µs

DC

Duty Cycle

Full Load

q

45

50

60

%

Switch Saturation Voltage

0.4

0.7

V

0.5

0.8

V

ELECTRICAL C

C

HARA TERISTICS

PACKAGE/ORDER I FOR ATIO

1

2

3

4

8

7

6

5

TOP VIEW

VIN

NC

SW

GND

SENSE

SHUTDOWN

NC

NC

N8 PACKAGE

8-LEAD PLASTIC DIP

LT1109 • PO102

1

2

3

4

8

7

6

5

TOP VIEW

SENSE

SHUTDOWN

NC

NC

NC

SW

GND

S8 PACKAGE

8-LEAD PLASTIC SOIC

LT1109 • PO103

GND

2

SW

3

1

Z PACKAGE

3-LEAD TO-92 PLASTIC

BOTTOM VIEW

OUT

V

LT1109 • POI01

LT1109CZ-5

LT1109CZ-12

ORDER PART

NUMBER

ORDER PART

NUMBER

S8 PART

MARKING

ORDER PART

NUMBER

LT1109CS8

LT1109CS8-5

LT1109CS8-12

LT1109CN8

LT1109CN8-5

LT1109CN8-12

1109

10905

10912

Operating Temperature Range ..................... 0

°C to 70°C

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

°C to 150°C

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

°C

Switch Current ........................................................ 1.2A

A

G

A

U

A

R

BSOLUTEXI

TI

S

(Voltages Referred to GND Pin)

SW Pin Voltage .......................................... – 0.4V to 50V

SHUTDOWN Pin Voltage ......................................... 6.0V

Maximum Power Dissipation ............................. 300mW