Browse Prior Art Database

Multiple-Output Buck Converter

IP.com Disclosure Number: IPCOM000113825D
Original Publication Date: 1994-Oct-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 2 page(s) / 49K

Publishing Venue

IBM

Related People

Lindfors, EA: AUTHOR [+2]

Abstract

Disclosed is a method to provide two outputs, at different voltages, from a single buck regulator using a special magnetic inductor.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 70% of the total text.

Multiple-Output Buck Converter

      Disclosed is a method to provide two outputs, at different
voltages, from a single buck regulator using a special magnetic
inductor.

      The Figure is a schematic view of a circuit providing a first
voltage output, VO1, driving a first load resistance 10, and a second
voltage output, VO2, driving a second load resistance 12, from the
topology of a single buck regulator.  The circuit includes a Field
Effect Transistor FET 14, rectifiers 16 and 18, capacitors 20 and 22,
and a coupled inductor 24 having coils 26 and 28.  A DC input voltage
Vn is provided for the circuit, which includes an on/off control 30.

      When FET 14 is ON, coil 26, first load 10, rectifier 16, and
filter capacitor 20 act as a normal buck regulator, charging the
filter capacitor 20 to provide the output voltage VO1 across the load
10.  During this time, energy is stored in the inductor 24 because of
the winding polarities of the coupled inductor, as indicated by the
winding polarity dots at opposite ends of the device.

      When FET 14 turns OFF, rectifier 16, which acts as a
conventional free-wheeling diode, maintains current flow through coil
26 and through first load 10.  During this period, because the
voltage reverses across coupled inductor 24, the energy stored in the
inductor 24 during the ON time of FET 14 is allowed to flow in coil
28 to support second load 12.  Rectifier 18 acts as a half wave
rectifier during this period, produ...