SC1480AEVB datasheet(13/23 Pages) SEMTECH

No de pièce	SC1480AEVB

Description	DDR and DDR Memory VTT power Supply Controller

PDF	23 Pages

Scroll/Zoom	100%

Fabricant	SEMTECH [Semtech Corporation]

Site Internet	http://www.semtech.com

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13 / 23 page

 2003 Semtech Corp.

www.semtech.com

SC1480A

POWER MANAGEMENT

Applications Information (Cont.)

A = ambient temperature (°C)

D = power dissipation in (W)

JA = thermal impedance junction to ambient from

absolute maximum ratings (°C/W)

The power dissipation may be calculated as follows:

VCCA

•

Where:

VCCA = chip supply voltage (V)

VCCA = operating current (A)

g = gate drive voltage, typically 5V (V)

g = .ET gate charge, from the .ET datasheet (C)

f = switching frequency (kHz)

Inserting the following values as an example:

A = 85°C

JA = 100°C/W

VCCA = 5V

VCCA = 1100µA (data sheet maximum)

g = 5V

g = 60nC

f = 342kHz

gives us:

108

342

1100

•

−

and

100

108

•

As can be seen, the heating effects due to internal power

dissipation are practically negligible, thus requiring no

special consideration thermally during layout.

SC1480AEVB Fiches technique(PDF) 13 Page - Semtech Corporation