over the full Operating Junction Temperature (T

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

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

Ω. See (Note 5). (Continued)

Symbol

Parameter

Conditions

Min

Typ

Max

Units

Off Timer

t

OFF

Minimum Off-time

260

ns

Regulation and Over-Voltage Comparators (FB Pin)

V

REF

FB regulation threshold

2.445

2.50

2.550

V

FB over-voltage threshold

2.9

V

FB bias current

1nA

Thermal Shutdown

T

SD

Thermal shutdown temperature

175

˚C

Thermal shutdown hysteresis

20

˚C

Thermal Resistance

θ

JA

Junction to Ambient, 0 LFPM

Air Flow

SDC Package

MXA Package

40

40

˚C/W

θ

JC

Junction to Case

SDC Package

MXA Package

5.2

5.2

˚C/W

Note 1: Absolute Maximum Ratings are limits beyond which damage to the device may occur. Operating Ratings are conditions under which operation of the device

is intended to be functional. For guaranteed specifications and test conditions, see the Electrical Characteristics.

Note 2: The human body model is a 100pF capacitor discharged through a 1.5k

Ω resistor into each pin.

Note 4: For detailed information on soldering plastic TSSOP and LLP packages refer to the Packaging Data Book available from National Semiconductor

Corporation.

Note 5: Typical specifications represent the most likely parametric norm at 25˚C operation.

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