EP0339963A2
Expired / Lapsed
EP
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Synchronous rectifier
Assignee: General Electric Co
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Filing: 1989-04-26
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Granted: —
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Expires: 2009-04-26
Abstract
Abstract A synchronous rectifier (20) is able to operate at higher frequencies and provides an output having lower noise than prior art FET synchronous rectifier system by using field effect switching devices (42, 44) which contain only one conductivity type of semiconductor material and connected in parallel with high speed, low charge storage diodes (46, 48). Schottky diodes are preferred. Conventional FETs may be used when paralleled with a Schottky diode which prevents the FET'S parasitic internal diode from becoming conductive.
Inventors
- 👤 Khai Doan The Ngo
- 👤 John Palmer Walden
- 👤 Robert Louis Steigerwald
- 👤 Bantval Jayant Baliga
- 👤 Charles Steven Korman
- 👤 Hseuh-Rong Chang
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 17:10
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/202; H02; H02M; H02M7/00; H02M7/02; H02M7/04; H02M7/12; H02M7/21; H02M7/217; H10D30/60; H10D30/63; H10D30/635
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
88 words
A synchronous rectifier circuit of the type including switching devices whose conductive state is controlled by an external signal and a transformer for applying an AC voltage to said switching devices for rectification, wherein: each of said switching devices comprising: an insulated gate field effect transistor in which all of the semiconductor material is of a single conductivity type, and a diode connected in parallel with said field effect transistor in an orientation to conduct transient currents in its forward direction when said field effect transistor is non-conductive.
Claim 2
Dependent Claim
88 words
A synchronous rectifier circuit of the type including switching devices whose conductive state is controlled by an external signal and a transformer for applying an AC voltage to said switching devices for rectification, wherein: each of said switching devices comprising: an insulated gate field effect transistor in which all of the semiconductor material is of a single conductivity type, and a diode connected in parallel with said field effect transistor in an orientation to conduct transient currents in its forward direction when said field effect transistor is non-conductive.
Claim 3
Dependent Claim
14 words
The synchronous rectifier circuit recited in Claim 1 wherein: said diodes are Schottky diodes.
Claim 4
Dependent Claim
76 words
A synchronous rectifier circuit of the type including switching devices whose conductive state is controlled by an external signal and a transformer for applying an AC voltage to said switching devices for rectification, wherein: each of said switching devices comprising: an insulated gate field effect transistor; and a Schottky diode connected in parallel with said field effect transistor in an orientation to conduct transient currents in its forward direction when said field effect transistor is non-conductive.
Claim 5
Dependent Claim
76 words
A synchronous rectifier circuit of the type including switching devices whose conductive state is controlled by an external signal and a transformer for applying an AC voltage to said switching devices for rectification, wherein: each of said switching devices comprising: an insulated gate field effect transistor; and a Schottky diode connected in parallel with said field effect transistor in an orientation to conduct transient currents in its forward direction when said field effect transistor is non-conductive.
Claim 6
Dependent Claim
31 words
The synchronous rectifier circuit recited in any preceding claim wherein: each of said switching devices consists of a single chip in which said field effect transistor and said diode are integrated.
Claim 7
Dependent Claim
44 words
The synchronous rectifier circuit recited in Claim 4 wherein: said integrated switching device is a three terminal device having said diode connected between the source and drain electrodes of said field effect transistor with the three terminals being the source, drain and gate terminals.
Claim 8
Dependent Claim
95 words
The synchronous rectifier circuit recited in any preceding claim wherein said transformer includes a secondary winding including first and second portions connected in common to a center tap and having first and second outer terminals, respectively, further comprising: an output filter having an input terminal connected to said center tap of said transformer, an output terminal and a reference terminal; a first one of said switching devices connected between said first outer terminal and said reference terminal; and a second one of said switching devices connected between said second outer terminal and said reference terminal.
Claim 9
Dependent Claim
39 words
The synchronous rectifier circuit recited in any preceding claim wherein: said switching devices are oriented with the anode of said diode connected to said reference terminal for positive DC voltages at said output terminal relative to said reference terminal.
Claim 10
Dependent Claim
36 words
The synchronous rectifier circuit recited in any preceding claim wherein: said transformer is designed to operate at frequencies in excess of 2 MHz; and said diodes have a reverse recovery time of less than 100 nanoseconds.
References Cited (Backward Citations)
No citation records indexed.
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