Single-Ended Forward Converter
A single-ended forward converter of the present invention, has first and second switching element comprises a pair Lus N-Channel FET, a first driving circuit comprises the series-connected circuit of the first voltage drop resistor and first zener diode for driving first Lus N-Channel FET, a second driving circuit comprises the series-connected circuit of the second voltage drop resistor and second zener diode for driving second Lus N-Channel FET.
1. Field of the Invention
The present invention related to enhancement mode Lus FET for single-ended forward converter, especially Lus FET with novel structures replacing prior art static shielding diode (SSD), or body diode, or intrinsic diode, in prior art FET may be with polarity reversed are taught by the ROC. TW. Pat. Nos. 1295,527; 1295,528; 1301,013; 1301,014; 1301,015. According to such philosophy of the present invention, the Single-ended forward converter may be achieved with two Lus N-Channel FET, or two Lus P-Channel FET.
2. Description of Related Art
As shown in
Each of the first and second switching element F1, F2, comprises a prior art N-Channel FET shown in
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In order to provide Lus FET that may elevate the efficiency of single-ended forward converter, the present invention is proposed the following object:
The first object of the present invention to provide Lus FET for a single-ended forward converter, in which the converter simplicity is improved.
The second object of the present invention provide a Lus FET for single-ended forward converter, can be eliminate the destruction of prior art FET, and windings due to a large current.
According to the defects of the prior art technology discussed above, a novel solution, the Lus FET is proposed in the present invention, which provides higher efficiency in single-ended forward converter.
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Each of the first and second switching element Q1, Q2, comprises a pair Lus N-Channel FET shown in
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Claims
1. A single-ended forward converter comprises:
- a first Lus N-Channel FET connected in series with a secondary winding of a transformer of said single-ended forward converter;
- a second Lus N-Channel FET connected in parallel with a series circuit constituted by the secondary winding of said transformer and said first Lus N-Channel FET;
- a first driving circuit connected in parallel with a secondary winding of said a transformer for driving first Lus N-Channel FET; and
- a second driving circuit connected in parallel with second Lus N-Channel FET for driving second Lus N-Channel FET.
2. A single-ended forward converter as in claim 1, wherein said driving circuit comprises a first and second driving element.
3. A single-ended forward converter as in claim 2, wherein said first driving element comprises the series-connected circuit of the first voltage drop resistor and first zener diode.
4. A single-ended forward converter as in claim 3, wherein said first voltage drop resistor and said first zener diode can be replace first driving resistor and second driving resistor.
5. A single-ended forward converter as in claim 2, wherein said second driving element comprises the series-connected circuit of the second voltage drop resistor and second zener diode.
6. A single-ended forward converter as in claim 5, wherein said second voltage drop resistor and said second zener diode can be replace third driving resistor and fourth driving resistor.
7. A single-ended forward converter as in claim 1, wherein:
- said first terminal of first voltage drop resistor connected to terminal A of secondary winding of said transformer;
- said secondary terminal of first voltage drop resistor and said first terminal of first zener diode connected together to said gate of Lus N-Channel FET; and
- said second terminal of first zener diode connected to said terminal B of second winding of said transformer.
8. A single-ended forward converter as in claim 1, wherein:
- said first terminal of second voltage drop resistor connected to drain of second Lus N-Channel FET and drain of first Lus N-Channel FET;
- said second terminal of second voltage drop resistor and said first terminal of second zener diode connected together to said gate of second Lus N-Channel FET; and
- said second terminal of second zener diode connected to terminal A of secondary Winding of said transformer and said source of second Lus N-Channel FET.
9. A single-ended forward converter comprises:
- a first Lus P-Channel FET connected in series with a secondary winding of a transformer of said single-ended forward converter;
- a second Lus P-Channel FET connected in parallel with a series circuit constituted by the secondary winding of said transformer and said first Lus P-Channel FET;
- a first driving circuit connected in parallel with a secondary winding of said a transformer for driving first Lus P-Channel FET; and
- a second driving circuit connected in parallel with second Lus P-Channel FET for driving second Lus P-Channel FET.
10. A single-ended forward converter as in claim 9, wherein said driving circuit comprises a first and second driving element.
11. A single-ended forward converter as in claim 10, wherein said first driving element comprises the series-connected circuit of the first driving resistor and second driving resistor.
12. A single-ended forward converter as in claim 11, wherein said first driving resistor and second driving resistor can be replace first voltage drop resistor and first zener diode.
13. A single-ended forward converter as in claim 10, wherein said second driving element comprises the series-connected circuit of the third driving resistor and fourth driving resistor.
14. A single-ended forward converter as in claim 13, wherein said third driving resistor and fourth driving resistor can be replace second voltage drop resistor and second zener diode.
15. A single-ended forward converter as in claim 9, wherein:
- said first terminal of first driving resistor connected to terminal A of secondary winding of said transformer;
- said second terminal of first driving resistor and said first terminal of second driving resistor connected together to said gate of first Lus P-Channel FET; and
- said terminal of second driving resistor connected to terminal B of secondary Winding of said transformer.
16. A single-ended forward converter as in claim 9, wherein:
- said first terminal of third driver resistor connected to drain of first Lus P-Channel FET and drain of second Lus P-Channel FET;
- said second terminal of third driving resistor and said first terminal of fourth driving resistor connected together to said gate of second Lus P-Channel FET; and
- said second terminal of fourth driving resistor connected to terminal B of secondary winding of said transformer and said source of second Lus P-Channel FET.
Type: Application
Filed: Sep 8, 2009
Publication Date: Mar 10, 2011
Inventor: Chao-Cheng Lu (Taipei)
Application Number: 12/584,404
International Classification: H02M 3/335 (20060101);