Absolute Maximum Ratings (Note 1)

If Military/Aerospace specified devices are required,

please contact the National Semiconductor Sales Office/

Distributors for availability and specifications.

Storage Temperature Range

−65˚C to +150˚C

Operating Junction

Temperature Range

−40˚C to +125˚C

Lead Temp. (Soldering, 5 sec.)

300˚C

Power Dissipation (Note 2)

Internally Limited

FB Pin Voltage

−0.4V to +6V

SW Pin Voltage

−0.4V to +40V

Input Supply Voltage

−0.4V to +14.5V

Shutdown Input Voltage

(Survival)

−0.4V to +14.5V

θ

265˚C/W

ESD Rating (Note 3)

Human Body Model

Machine Model

2kV

200V

Electrical Characteristics

Limits in standard typeface are for T

(−40˚C

≤ T

J

≤ +125˚C). Unless otherwise specified: V

Symbol

Parameter

Conditions

Min

(Note 4)

Typical

(Note 5)

Max

(Note 4)

Units

V

IN

Input Voltage

2.7

14

V

I

SW

Switch Current Limit

(Note 6)

1.0

1.5

A

R

Switch ON Resistance

I

500

650

m

Ω

SHDN

TH

Shutdown Threshold

Device ON

1.5

V

Device OFF

0.50

I

SHDN

Shutdown Pin Bias Current

V

0

µA

V

0

2

V

FB

Feedback Pin Reference

Voltage

V

1.205

1.230

1.255

V

I

FB

Feedback Pin Bias Current

V

60

nA

I

Q

Quiescent Current

V

2.1

3.0

mA

V

1.1

2

V

400

500

µA

V

0.024

1

FB Voltage Line Regulation

2.7V

≤ V

IN

≤ 14V

0.02

%/V

F

SW

Switching Frequency

“X” Option

1.15

1.6

1.85

MHz

“Y” Option

0.40

0.60

0.8

D

MAX

Maximum Duty Cycle

“X” Option

87

93

%

“Y” Option

93

96

I

L

Switch Leakage

Not Switching V

1

µA

Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the component may occur. Electrical specifications do not apply when operating the

device outside of the limits set forth under the operating ratings which specify the intended range of operating conditions.

the junction-to-ambient thermal resistance for the SOT-23 package,

at any ambient temperature for designs using this device can be calculated using the formula:

If power dissipation exceeds the maximum specified above, the internal thermal protection circuitry will protect the device by reducing the output voltage as required

to maintain a safe junction temperature.

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: Limits are guaranteed by testing, statistical correlation, or design.

Note 5: Typical values are derived from the mean value of a large quantity of samples tested during characterization and represent the most likely expected value

of the parameter at room temperature.

Note 6: Switch current limit is dependent on duty cycle (see Typical Performance Characteristics). Limits shown are for duty cycles

≤ 50%.

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