SM645/SM646/SM647

4/90 Rev 1.1 2/94

Copyright

© 1994

11861 Western Avenue

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(714) 898-8121

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FEATURES

••••• Equivalent to the Unitrode PIC 645, 646, 647

••••• 15A current capability

••••• Cost saving design reduces size, improves efficiency,

reduces noise and RFI

••••• High operating frequency (to > 100KHz) results in

smaller inductor-capacitor filter and improved power

supply response time

••••• High operating efficiency at 7A typical performance -

Rise and fall time < 300ns

Efficiency > 85%

HIGH RELIABILITY FEATURES

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♦ Available with high reliability processing

DESCRIPTION

The SM645/646/647 series of Power Output Stages are espe-

cially designed to be driven with standard PWM integrated

circuits to form an efficient switching power supply. The SM645,

SM646 and SM647 are optimized for non-isolated Buck and

Buck-Boost application. The hybrid circuit construction utilizes

thick film resistors on a beryllia substrate for maximum thermal

conductivity and resultant low thermal impedance. All of the

active elements in the hybrid are fully passivated.

SWITCHING REGULATOR

POWER OUTPUT STAGES

SM645/SM646/SM647

FUNCTIONAL DIAGRAM