Source : Switching Power Supply Design, Third EditionAbraham I. Pressman, KeithBillings, Taylor MoreycoverAbraham I. Pressman, Keith Billings, Taylor MoreyiSwitching Power Supply DesignThird EditionAbraham I. PressmanKeith BillingsTaylor MoreyNew York Chicago San Francisco Lisbon London Madrid Mexico City Milan New DelhiSan Juan Seoul Singapore Sydney TorontoAbraham I. Pressman, Keith Billings, Taylor MoreyiiLibrary of Congress Cataloging-in-Publication DataMcGraw-Hill books are available at special quantity discounts to use as premiums and sales promotions, or for use incorporate training programs. To contact a special sales representative, please visit the Contact Us page atwww.mhprofessional.Switching Power Supply Design, Third EditionCopyright ? 2009 by The McGraw-Hill Companies.All rights reserved. Printed in the United States of America. Except as permitted under the Copyright Act of 1976, nopart of this publication may be reproduced or distributed in any form or by any means, or stored in a database orretrieval system, without the