Absolute Maximum Ratings (Note 1)

If Military/Aerospace specified devices are required,

please contact the National Semiconductor Sales Office/

Distributors for availability and specifications.

V

IN

7.5V

SW Voltage

21V

FB Voltage (Note 2)

7V

V

SHDN Voltage

7.5V

FSLCT

7.5V

Maximum Junction

Temperature

150˚C

Power Dissipation(Note 4)

Internally Limited

Lead Temperature

300˚C

Vapor Phase (60 sec.)

215˚C

Infrared (15 sec.)

220˚C

ESD Susceptibility

(Note 5)

Human Body Model

2kV

Machine Model

200V

Operating Conditions

Operating Junction

Temperature Range (Note 6)

−40˚C to +125˚C

Storage Temperature

−65˚C to +150˚C

Supply Voltage

2.7V to 7V

Maximum Output Voltage

20V

Electrical Characteristics

Specifications in standard type face are for T

ture Range (T

Symbol

Parameter

Conditions

Min

(Note 6)

Typ

(Note 7)

Max

(Note 6)

Units

I

Q

Quiescent Current

FB = 2V (Not Switching)

1.3

2.0

mA

V

0.1

2.0

µA

V

FB

Feedback Voltage

1.2285

1.26

1.2915

V

I

CL(Note 8)

Switch Current Limit

V

2.45

A

V

2.1

V

2.2

%V

∆V

IN

Feedback Voltage Line

Regulation

2.7V

≤ V

IN

≤ 7V

0.085

0.15

%/V

I

B

FB Pin Bias Current (Note

10)

35

250

nA

I

SS

SS Pin Current

7.5

11

13

µA

V

SS

SS Pin Voltage

1.2090

1.2430

1.2622

V

IN

Input Voltage Range

2.7

7

V

g

m

Error Amp Transconductance

∆I = 5µA

40

87

135

µmho

A

V

Error Amp Voltage Gain

78

V/V

D

MAX

Maximum Duty Cycle

85

92.5

%

f

S

Switching Frequency

FSLCT = Ground

450

615

750

kHz

FSLCT = V

IN

0.9

1.25

1.5

MHz

I

SHDN

Shutdown Pin Current

V

2.4

5.0

µA

V

0.3

1.2

I

L

Switch Leakage Current

V

0.2

8.0

µA

R

DSON

Switch R

DSON

V

0.15

0.4

Ω

Th

SHDN

Shutdown Threshold

Output High

1.2

0.8

V

Output Low

0.8

0.3

V

UVP

On Threshold

2.3

2.5

V

Off Threshold

2.6

2.7

V

Note 1: Absolute maximum ratings are limits beyond which damage to the device may occur. Operating Ratings are conditions for which the device is intended to

be functional, but device parameter specifications may not be guaranteed. For guaranteed specifications and test conditions, see the Electrical Characteristics.

Exceeding the maximum allowable power dissipation will cause excessive die temperature, and the regulator will go into thermal shutdown.

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