Multi-Resonance Converter

• US 20070297199A1
• Filed: 11/21/2005
• Published: 12/27/2007
• Est. Priority Date: 11/29/2004
• Status: Active Grant

• Current Assignee: NXP B.V. (NXP Semiconductors NV)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Elferich, Reinhold, De Groot, Humphrey, Sauerlander, Georg, Schetters, Cornelis
• Granted Patent: US 7,688,600 B2
• Time in Patent Office: Days
• US Class Current: 363/21.02
• CPC Class Codes: H02M 3/3382 in a push-pull circuit arrangement

Abstract

In a multi-resonance converter for converting a first DC voltage into a second DC voltage, wherein the output of a half-bridge comprising semiconductor switches is connected through a resonance capacitor to the primary winding of a transformer and the secondary winding of the transformer, together with rectifier elements, an output inductor and an output capacitor, forms a current output, it is proposed that a controller, which can be supplied which the voltage across the output capacitor and a reference voltage, should control the semiconductor switches alternately so that one of the semiconductor switches is respectively turned on at a predetermined time after the other semiconductor switch is turned off. Preferably, the frequency is controlled in an upper range of the drawn power while in a lower range of the drawn power, the mark-space ratio is controlled for selected respectively constant frequencies.

Claims

1. A multi-resonance converter for converting a first DC voltage into a second DC voltage, wherein the output of a half-bridge comprising semiconductor switches (S1, S2) is connected through a resonance capacitor (Cr) to the primary winding (P) of a transformer (Tr) and the secondary winding (S) of the transformer (Tr) together with rectifier elements (D1, D2), an output inductor (Lo) and an output capacitor (Co) forms a current output, characterized in that a controller (R), which can be supplied with the voltage across the output capacitor (Co) and a reference voltage, controls the semiconductor switches (S1, S2) alternately so that one of the semiconductor switches (S1, S2) is respectively turned on at a predetermined time after the other semiconductor switch (S2, S1) is turned off.

2. A converter as claimed in claim 1, characterized in that the frequency is controlled in an upper range of the drawn power.

3. A converter as claimed in claim 1, characterized in that in a lower range of the drawn power, the mark-space ratio is controlled for selected respectively constant frequencies.

4. A converter as claimed in claim 3, characterized in that in the lower power range, the periods for the selected frequencies are given by T1p=(n+½

)*T0, where n is an integer depending on the drawn power and T0 is the period of the oscillation, the frequency of which is dictated by the resonance capacitor (Cr) and the series circuit of the stray inductance (Lr) and the main inductance (Lm) of the transformer (Tr).

5. A converter as claimed in claim 1, characterized in that the controller (R) is formed by a programmable device, in which a period is derived as a function of the voltage across the output capacitor (Co) and the reference voltage, in that the derived period is compared with periods of the maximum frequency and the selected frequencies, and in that the control signals supplied to the semiconductor switches (S1, S2) are derived as a function of the frequency and the mark-space ratio.

6. A converter as claimed in claim 1, characterized in that the secondary winding (S) has a center tap and the ends of the secondary winding (S) are respectively connected to a rectifier element (D1, D2).