5

LT1959

Switching Frequency

BOOST Pin Current

Maximum Load Current

Maximum Load Current

Switch Voltage Drop

Current Limit Foldback

*See “More Than Just Voltage Feedback” in the Applications Information section.

TEMPERATURE (

°C)

–50

550

540

530

520

510

500

490

480

470

460

450

100

1959 G11

–25

0

25

50

75

125

INPUT VOLTAGE (V)

5

2.6

2.8

3.2

3.4

3.6

9

13

15

4.4

1959 G13

3.0

711

3.8

4.0

4.2

L= 10

µH

L= 5

µH

L= 3

µH

L= 1.8

µH

SWITCH CURRENT (A)

0

0

10

20

40

30

60

50

12

3

45

1959 G15

80

70

100

90

DUTY CYCLE = 100%

INPUT VOLTAGE (V)

4

4.0

4.2

4.4

12

1959 G14

3.8

3.6

610

814

3.4

3.2

3.0

L= 10

µH

L= 5

µH

L= 3

µH

L= 1.8

µH

OUTPUT VOLTAGE (%)

0

5

6

7

80

1959 G16

4

3

20

40

60

100

2

1

0

FOLDBACK

CHARACTERISTICS

CURRENT

SOURCE

LOAD

RESISTOR

LOAD

MOS LOAD

POSSIBLE UNDESIRED

STABLE POINT FOR

CURRENT SOURCE

LOAD*

JUNCTION TEMPERATURE (

°C)

–50

1.4

1.2

1.0

0.8

0.6

0.4

100

1959 G17

–25

0

25

50

75

125

SHUTDOWN

SWITCH CURRENT (A)

0

250

200

400

125

°C

25

°C

350

300

45

1959 G18

150

100

50

0

1

2

3

500

450

–40

°C

Frequency Foldback

FEEDBACK PIN VOLTAGE (V)

0

500

400

300

200

100

0

0.2

0.4

0.6

0.8

1959 • G10

1.0

1.2

SWITCHING

FREQUENCY

FEEDBACK

PIN CURRENT