3

LT1617/LT1617-1

TYPICAL PERFOR A CE CHARACTERISTICS

Switch Saturation Voltage

Quiescent Current

Feedback Pin Voltage and

Bias Current

TEMPERATURE (

°C)

–50

–25

0

25

50

75

100

1617/-1 G01

0.60

0.55

0.50

0.45

0.40

0.35

0.30

0.25

0.20

0.15

0.10

TEMPERATURE (

°C)

–50

1617/-1 G02

–1.25

–1.24

–1.23

–1.22

–1.21

–1.20

5

4

3

2

1

0

CURRENT

VOLTAGE

–25

0

25

50

75

100

TEMPERATURE (

°C)

1617/-1 G03

25

23

21

19

17

15

–50

–25

0

25

50

75

100

NOT SWITCHING

PI FU CTIO S

SW (Pin 1): Switch Pin. This is the collector of the internal

NPN power switch. Minimize the metal trace area con-

nected to this pin to minimize EMI.

GND (Pin 2): Ground. Tie this pin directly to the local

ground plane.

NFB (Pin 3): Feedback Pin. Set the output voltage by

selecting values for R1 and R2 (see Figure 1):

R

V

R

OUT

1

123

123

2

=

−

+

.

.

•

SHDN (Pin 4): Shutdown Pin. Tie this pin to 0.9V or higher

to enable the device. Tie below 0.25V to turn off the device.

capacitor as close to the device as possible.

TEMPERATURE (

°C)

1617/-1 G04

550

500

450

400

350

300

250

–50

–25

0

25

50

75

100

TEMPERATURE (

°C)

1617/-1 G05

400

350

300

250

200

150

100

50

0

–50

–25

0

25

50

75

100

LT1617-1

LT1617

SHUTDOWN PIN VOLTAGE (V)

1617/-1 G06

25

20

15

10

5

0

0

5

10

15

25

°C

100

°C

Switch Off Time

Shutdown Pin Current

Switch Current Limit