Absolute Maximum Ratings (Note 1)

If Military/Aerospace specified devices are required,

please contact the National Semiconductor Sales Office/

Distributors for availability and specifications.

VIN to RTN

33V

BST to RTN

47V

SW to RTN (Steady State)

-1.5V

ESD Rating (Note 2)

Human Body Model

2kV

BST to VCC

33V

VIN to SW

33V

BST to SW

14V

VCC to RTN

14V

SGND to RTN

-0.3V to +0.3V

Current out of ISEN

See Text

SS to RTN

-0.3V to 4V

All Other Inputs to RTN

-0.3 to 7V

Storage Temperature Range

-65˚C to +150˚C

JunctionTemperature

150˚C

Operating Ratings (Note 1)

VIN

8.0V to 30V

Junction Temperature

−40˚C to + 125˚C

apply over the full Operating Junction Temperature (T

design, or statistical correlation. Typical values represent the most likely parametric norm at T

reference purposes only. Unless otherwise stated the following conditions apply: V

Ω. See (Note 5).

Symbol

Parameter

Conditions

Min

Typ

Max

Units

Start-Up Regulator, V

CC

V

V

6.6

7

7.4

V

V

I

V

1.3

V

V

0 mA

≤ I

CC

≤ 5 mA

140

Ω

V

V

9.7

mA

UVLO

VCC

V

threshold

V

5.7

V

UVLO

V

150

mV

UVLO

100 mV overdrive

3

µs

I

Non-switching, FB = 3V

0.5

0.8

mA

I

RON/SD = 0V

95

200

µA

Switch Characteristics

Rds(on)

Buck Switch Rds(on)

I

0.33

0.7

Ω

UVLO

GD

Gate Drive UVLO

V

3.0

4.4

5.5

V

UVLO

480

mV

Softstart Pin

Pull-up voltage

2.5

V

Internal current source

12.3

µA

Current Limit

I

LIM

Threshold

Current out of ISEN

1

1.25

1.5

A

Resistance from ISEN to

SGND

130

m

Ω

Response time

150

ns

On Timer

t

On-time

V

Ω

2.1

2.8

3.6

µs

t

On-time

V

Ω

950

ns

Shutdown threshold

Voltage at RON/SD rising

0.45

0.8

1.2

V

Threshold hysteresis

Voltage at RON/SD falling

37

mV

Off Timer

t

OFF

Minimum Off-time

250

ns

Regulation and Over-Voltage Comparators (FB Pin)

V

REF

FB regulation threshold

SS pin = steady state

2.440

2.5

2.550

V

FB over-voltage threshold

2.9

V

www.national.com

4