CN203326886U - Soft switching DC-DC converter - Google Patents
Soft switching DC-DC converter Download PDFInfo
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- CN203326886U CN203326886U CN201320124456XU CN201320124456U CN203326886U CN 203326886 U CN203326886 U CN 203326886U CN 201320124456X U CN201320124456X U CN 201320124456XU CN 201320124456 U CN201320124456 U CN 201320124456U CN 203326886 U CN203326886 U CN 203326886U
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
- Y02B70/10—Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes
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Abstract
The utility model relates to a soft switching DC-DC converter which comprises an input portion and an output portion, wherein the input portion is connected with the output portion through a transformer T1 in a coupling mode. The input portion comprises an LLC resonance network topological circuit, an LLC dedicated chip IC1 and an isolation feedback circuit. The LLC resonance network topological circuit comprises an LLC resonance circuit, an MOS tube Q1, an MOS tube Q2and a half bridge circuit structure formed by the LLC resonance circuit and the MOS tube Q1 and the MOS tube Q2. The isolation feedback circuit comprises a photoelectric coupler and a parallel connection voltage-stabilization integrated circuit IC2, a primary side of the transformer T1, a primary level of the photoelectric coupler and the parallel connection voltage-stabilization integrated circuit IC2 are in series connection, and a secondary level of the photoelectric coupler is connected with the LLC dedicated chip IC1. The output portion is a full-wave rectification circuit connected with a secondary side of the transformer T1. The soft switching DC-DC converter can greatly reduce the switching loss on a switching tube and a diode, influences of input on output are small, output noise is low, and interference for load is low.
Description
Technical field
The present invention relates to electric and electronic technical field, specifically, relate to a kind of soft switch DC-DC converter.
Background technology
Direct-current switch power supply is the DC power supply that has DC converter and output voltage stabilization or change as requested, and it is input as direct current or alternating current.The core of direct-current switch power supply is the DC-DC converter, and this converter is a kind of direct current to be converted to the converter of another kind of or multiple direct current energy, is the critical piece of Switching Power Supply.The DC power supply DC-DC converter of application great majority adopt the hard switching circuit in the market, switching tube and output rectifier diode are all worked under the control of hard switching, and voltage and current stress is all very large, switching noise is also large, is easy to output circuit is impacted.
Summary of the invention
The output that the object of the invention is to exist for existing Switching Power Supply DC-DC converter disturbs the problems referred to above such as large, that switching noise is large, provide a kind of output noise low, to load disturbance little soft switch DC-DC converter, this converter can reduce the switching loss on switching tube and diode greatly, and input is little on the output impact.
Technical scheme of the present invention is: a kind of soft switch DC-DC converter, comprise input part and efferent, and between input part and efferent, by transformer T1, be of coupled connections; Input part comprises LLC resonant network topological circuit, LLC special chip IC 1 and isolation feedback circuit, LLC resonant network topological circuit comprises LLC resonant circuit and two metal-oxide-semiconductor Q1, Q2, LLC resonant circuit and two half bridge circuit structures that metal-oxide-semiconductor Q1, Q2 form, isolation feedback circuit comprises photoelectrical coupler and parallel voltage-stabilizing integrated circuit (IC) 2, elementary and the parallel voltage-stabilizing integrated circuit (IC) 2 of the former limit of transformer T1, photoelectrical coupler is connected in series, and the secondary and LLC special chip IC 1 of photoelectrical coupler is connected; Efferent is the full-wave rectifying circuit be connected with transformer T1 secondary.
Preferably, the LLC resonant circuit also is connected with short-circuit protection circuit, the series-parallel circuit that this short-circuit protection circuit is comprised of coupling capacitance C4, diode D3, diode D4, resistance R 9 and capacitor C 9.
Preferably, the LLC resonant circuit is composed in series by the former limit of transformer T1, resonant inductance L2 and resonance capacitor C 2.
Preferably, the distance between the former limit of transformer T1 and secondary is at least 6mm.
Preferably, isolation feedback circuit also comprises a bleeder circuit, and this bleeder circuit one end is connected in the input of photoelectrical coupler, and an end is connected to the earth terminal of parallel voltage-stabilizing integrated circuit (IC) 2.
Preferably, bleeder circuit is composed in series by divider resistance R20, divider resistance R21 and divider resistance R22.
Preferably, parallel voltage-stabilizing integrated circuit (IC) 2 adopts TL431.
Preferably, full-wave rectifying circuit is the band centre cap full-wave rectifying circuit be comprised of diode D6, diode D7, filter capacitor C14 and filter capacitor C15.
Beneficial effect of the present invention is: between input part of the present invention and efferent, by transformer coupled, be connected, input part is provided with semibridge system LLC resonant network topological circuit and isolation feedback circuit, the former limit of transformer T1 switching tube is the no-voltage conducting, the output rectifier diode is operated in the zero current mode, switching loss on switching tube and diode reduces greatly, input reduces greatly on the impact of output, and output noise is low, low to load disturbance; And the former limit of transformer T1 is connected with isolation feedback circuit, input adopts the off-line type feedback with output, existing feedback output voltage function, the bootstrapping power supply is provided can to again LLC special chip IC 1, input is greater than AC8KV to the output isolation voltage, distance between the former limit of transformer T1 and secondary is at least 6mm, and input is less than 3 pico farads to output capacitance, and the interference of input reduces to output greatly by transformer coupled.The present invention also is provided with short-circuit protection circuit, has realized the function of output short-circuit protection and output under-voltage protection.
The accompanying drawing explanation
Fig. 1 is structured flowchart of the present invention.
Fig. 2 is circuit theory diagrams of the present invention.
Embodiment
Below in conjunction with accompanying drawing, the invention will be further described.
A kind of soft switch DC-DC converter provided by the invention, comprise input part and efferent, between input part and efferent, by transformer T1, is of coupled connections; Input part comprises LLC resonant network topological circuit, LLC special chip IC 1 and isolation feedback circuit, LLC resonant network topological circuit comprises LLC resonant circuit and two metal-oxide-semiconductor Q1, Q2, LLC resonant circuit and two half bridge circuit structures that metal-oxide-semiconductor Q1, Q2 form, isolation feedback circuit comprises photoelectrical coupler and parallel voltage-stabilizing integrated circuit (IC) 2, elementary and the parallel voltage-stabilizing integrated circuit (IC) 2 of the former limit of transformer T1, photoelectrical coupler is connected in series, and the secondary and LLC special chip IC 1 of photoelectrical coupler is connected; Efferent is the full-wave rectifying circuit be connected with transformer T1 secondary.
In order to realize output short-circuit protection and output under-voltage protection, above-mentioned LLC resonant circuit also is connected with short-circuit protection circuit, the series-parallel circuit that this short-circuit protection circuit is comprised of coupling capacitance C4, diode D3, diode D4, resistance R 9 and capacitor C 9.
Above-mentioned LLC resonant circuit is composed in series by the former limit of transformer T1, resonant inductance L2 and resonance capacitor C 2.
In order to realize that input is less than 3 pico farads to output capacitance, the distance between the former limit of transformer T1 and secondary is at least 6mm.
For the reference voltage of 2.5V being provided to parallel voltage-stabilizing integrated circuit (IC) 2, above-mentioned isolation feedback circuit also comprises a bleeder circuit, and this bleeder circuit one end is connected in the input of photoelectrical coupler, and an end is connected to the earth terminal of parallel voltage-stabilizing integrated circuit (IC) 2.
Above-mentioned bleeder circuit is composed in series by divider resistance R20, divider resistance R21 and divider resistance R22.
Above-mentioned parallel voltage-stabilizing integrated circuit (IC) 2 adopts TL431.
In order to reduce the quantity of diode, above-mentioned full-wave rectifying circuit is the band centre cap full-wave rectifying circuit be comprised of diode D6, diode D7, filter capacitor C14 and filter capacitor C15.
Operation principle: LLC special chip IC 1 provides driving pulse for metal-oxide-semiconductor Q1 and metal-oxide-semiconductor Q2, the square-wave generator that metal-oxide-semiconductor Q1, metal-oxide-semiconductor Q2 form produces square-wave voltage Vd by each switching with 50% duty ratio driven switch Q1 and switch Q2, then with a LLC resonant circuit, connect, this LLC resonant circuit and load are as a voltage divider, by changing the frequency of driving voltage Vd, change the impedance of LLC resonant circuit, this part impedance and reflection load will distribute input voltage.
By integrated stable voltage circuit IC2 in parallel and divider resistance R21, R22, R20, and the isolation feedback circuit that forms of luminous point coupler TLP521-1, the voltage fluctuation of exporting is fed back to, with regulated output voltage.When output voltage raises, the voltage of photoelectrical coupler feedback increases, and the frequency of VD will raise, otherwise will reduce.The series-parallel circuit be comprised of diode D5, capacitor C 5 and capacitor C 6 provides bootstrap voltage mode for LLC special chip IC 1, to maintain 1 normal operation of LLC special chip IC, is the isolation feedback circuit power supply simultaneously.The output short circuit protection circuit formed by coupling capacitance C4, diode D3, diode D4, resistance R 9 and capacitor C 9; when having large electric current to flow through C2; this electric circuit inspection to one positive pulse; by diode D3 and diode D4 rectification; capacitor C 9 and resistance R 4 filtering; to LLC special chip IC 1 the 9th pin, play the output short-circuit effect.Resistance R 16 forms voltage divider with resistance R 13, plays the output over-voltage protection effect.The output full-wave rectifying circuit is the band centre cap full-wave rectifying circuit be comprised of diode D6, diode D7, filter capacitor C14 and filter capacitor C15, for load provides voltage, resistance R 24, R25, R26 are output load resistance, prevent the unstable effect of circuit that output open circuit causes.
Claims (8)
1. a soft switch DC-DC converter, is characterized in that: comprise input part and efferent, be of coupled connections by transformer T1 between input part and efferent; Input part comprises LLC resonant network topological circuit, LLC special chip IC 1 and isolation feedback circuit, LLC resonant network topological circuit comprises LLC resonant circuit and two metal-oxide-semiconductor Q1, Q2, LLC resonant circuit and two half bridge circuit structures that metal-oxide-semiconductor Q1, Q2 form, isolation feedback circuit comprises photoelectrical coupler and parallel voltage-stabilizing integrated circuit (IC) 2, elementary and the parallel voltage-stabilizing integrated circuit (IC) 2 of the former limit of transformer T1, photoelectrical coupler is connected in series, and the secondary and LLC special chip IC 1 of photoelectrical coupler is connected; Efferent is the full-wave rectifying circuit be connected with transformer T1 secondary.
2. soft switch DC-DC converter according to claim 1; it is characterized in that: the LLC resonant circuit also is connected with short-circuit protection circuit, the series-parallel circuit that this short-circuit protection circuit is comprised of coupling capacitance C4, diode D3, diode D4, resistance R 4 and capacitor C 9.
3. according to claim 1 or the described soft switch DC-DC converter of 2 any one, it is characterized in that: the LLC resonant circuit is composed in series by the former limit of transformer T1, resonant inductance L2 and resonance capacitor C 2.
4. soft switch DC-DC converter according to claim 1 is characterized in that: the distance between the former limit of transformer T1 and secondary is at least 6mm.
5. soft switch DC-DC converter according to claim 1, it is characterized in that: isolation feedback circuit also comprises a bleeder circuit, this bleeder circuit one end is connected in the input of photoelectrical coupler, and an end is connected to the earth terminal of parallel voltage-stabilizing integrated circuit (IC) 2.
6. soft switch DC-DC converter according to claim 5, it is characterized in that: bleeder circuit is composed in series by divider resistance R20, divider resistance R21 and divider resistance R22.
7. according to claim 1 or the described soft switch DC-DC converter of 5 any one, it is characterized in that: parallel voltage-stabilizing integrated circuit (IC) 2 adopts TL431.
8. soft switch DC-DC converter according to claim 1, is characterized in that: the band centre cap full-wave rectifying circuit of full-wave rectifying circuit for being comprised of diode D6, diode D7, filter capacitor C14 and filter capacitor C15.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201320124456XU CN203326886U (en) | 2013-03-18 | 2013-03-18 | Soft switching DC-DC converter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201320124456XU CN203326886U (en) | 2013-03-18 | 2013-03-18 | Soft switching DC-DC converter |
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| Publication Number | Publication Date |
|---|---|
| CN203326886U true CN203326886U (en) | 2013-12-04 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201320124456XU Expired - Fee Related CN203326886U (en) | 2013-03-18 | 2013-03-18 | Soft switching DC-DC converter |
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| CN (1) | CN203326886U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103219886A (en) * | 2013-03-18 | 2013-07-24 | 青岛炬丰光电科技有限公司 | Soft switching DC-DC converter |
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2013
- 2013-03-18 CN CN201320124456XU patent/CN203326886U/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103219886A (en) * | 2013-03-18 | 2013-07-24 | 青岛炬丰光电科技有限公司 | Soft switching DC-DC converter |
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| Date | Code | Title | Description |
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| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20131204 Termination date: 20140318 |