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Thermal performance information – Vicor Micro Family of DC-DC Converter User Manual

Page 26

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Design Guide & Applications Manual

For Maxi, Mini, Micro Family DC-DC Converters and Configurable Power Supplies

Maxi, Mini, Micro Design Guide

Rev 4.9

vicorpower.com

Page 25 of 88

Apps. Eng. 800 927.9474

800 735.6200

The following pages contain temperature derating curves.

For additional thermal data, see the following link:

http://asp.vicorpower.com/calculators/calculators.asp?calc=5

Additional Thermal Data

6. Thermal Performance Information

The relevant nomenclature for the tabulated thermal information supplied in this section for the
Maxi, Mini, and Micro modules is defined as follows:

T

b

= baseplate temperature

T

a

= ambient temperature

P

out

= module output power

P

in

= module input power

η = module efficiency = P

out

/ P

in

P

diss

= module power dissipation = P

in

– P

out

= (1/η – 1)

P

out

Supplied thermal resistance values:

θ

bs

= baseplate-to-heatsink thermal resistance

θ

ba

= baseplate-to-ambient thermal resistance

Basis of output power versus ambient temperature derating curves:

(T

a

)

max

= (T

b

)

max

– θ

ba

P

diss

= (T

b

)

max

– θ

ba

(1/η – 1)

P

out

Simplified thermal management is one of the benefits of
using Vicor converters. High operating efficiency minimizes
heat loss, and the low-profile package features an easily
accessible, electrically isolated thermal interface surface.

Proper thermal management pays dividends in terms of
improved converter and system MTBFs, smaller size, and
lower product life-cycle costs. The following pages provide
guidelines for achieving effective thermal management of
Vicor converters.

Consideration should be given to the module baseplate
temperature during operation. The maximum baseplate
temperature specification for Maxi, Mini, and Micro is
100°C.

Enhanced module cooling can be achieved with free or
forced convection by using the appropriate heat sink. The
available Vicor heat sinks and thermal interface options
are available on the Vicor website.

This manual is related to the following products: