Milestone-Nomination:First Integrated PWM Controller for Switching Power Supplies


Docket Number: 2008-21

Proposal Link:

Proposed citation in English

The first integrated PWM Controller for Switching Power Supplies, 1975

Historic significance of this work: its importance to the evolution of electrical and computer engineering and science and its importance to regional/national/international development.

This invention is of significant technological importance as it revolutionized the technology of power supply design, ushering the industry into a conversion from large, heavy, and very inefficient linearly controled designs, to high-frequency switching solutions, a technology known before the advent of the SG1524, but ignored by all but the most sophisticated designers due to the perceived high cost, extreme complexity, and poor reliability – all of which disappeared with the introduction of the SG1524.
With this product, switching power supplies became ubiquitous and pervasive throughout all forms of electronic systems.

What features or characteristics set this work apart from similar achievements?

The SG1524 PWM controller IC was unique in its time as the semiconductor industry was then heavily involved in the advancement of digital computing circuits and what analog efforts there were, were largely relegated to operational amplifiers and linear voltage regulators. At that point, the semiconductor industry was committed to two separate processes – a gold-doped, high-speed digital process and a slower, more difficult to control analog process that had to be carefully separated from the digital manufacturing line. Because the control of switching power supplies required both analog and digital functions, the biggest challenge of the time was the combining both functions into one chip to be built with a single process, and the introduction of the SG1524 was one of the first practical examples to prove that this was possible.

Robert Mammano’s seminal IC design of the SG1524, and the many variations it inspired, tamed the complexity of SMPSs, shrinking their size and making them cost-effective and more reliable in countless applications.

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