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

2V

SHDN Voltage

7.5V

Maximum Junction Temp. T

J

(Note 2)

150˚C

Lead Temperature

(Soldering 10 sec.)

300˚C

Vapor Phase

(60 sec.)

215˚C

Infrared

(15 sec.)

220˚C

ESD Ratings (Note 3)

Human Body Model

Machine Model (Note 4)

2kV

200V

Operating Conditions

Junction Temperature

(Note 5)

−40˚C to +125˚C

Supply Voltage

2.2V to 7V

SW Voltage Max.

20.5V

Electrical Characteristics

Specifications in standard type face are for T

Range (T

Symbol

Parameter

Conditions

Min

(Note 5)

Typ

(Note 6)

Max

(Note 5)

Units

I

Q

Device Disabled

FB = 1.3V

40

70

µA

Device Enabled

FB = 1.2V

235

300

Shutdown

SHDN = 0V

0.01

2.5

V

FB

FeedbackTrip Point

1.189

1.237

1.269

V

I

CL

Switch Current Limit

275

260

350

400

400

mA

I

B

FB Pin Bias Current

FB = 1.23V (Note 7)

30

120

nA

V

IN

Input Voltage Range

2.2

7.0

V

R

DSON

Switch R

DSON

0.7

1.6

Ω

T

OFF

Switch Off Time

400

ns

I

SD

SHDN Pin Current

SHDN = V

080

nA

SHDN = V

15

SHDN = GND

0

I

L

Switch Leakage Current

V

0.05

5

µA

UVP

Input Undervoltage Lockout

ON/OFF Threshold

1.8

V

V

FB

Hysteresis

Feedback Hysteresis

8

mV

SHDN

Threshold

SHDN low

0.7

0.3

V

SHDN High

1.1

0.7

θ

JA

Thermal Resistance

220

˚C/W

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.

Note 3: The human body model is a 100 pF capacitor discharged through a 1.5 k

Ω resistor into each pin. The machine model is a 200 pF capacitor discharged

directly into each pin.

Note 4: ESD susceptibility using the machine model is 150V for SW pin.

Note 5: All limits guaranteed at room temperature (standard typeface) and at temperature extremes (bold typeface). All room temperature limits are 100%

production tested or guaranteed through statistical analysis. All limits at temperature extremes are guaranteed via correlation using standard Statistical Quality

Control (SQC) methods. All limits are used to calculate Average Outgoing Quality Level (AOQL).

Note 6: Typical numbers are at 25˚C and represent the most likely norm.

Note 7: Feedback current flows into the pin.

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