CN110535352B - Isolated DC-DC power supply circuit - Google Patents
Isolated DC-DC power supply circuit Download PDFInfo
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- CN110535352B CN110535352B CN201910917313.6A CN201910917313A CN110535352B CN 110535352 B CN110535352 B CN 110535352B CN 201910917313 A CN201910917313 A CN 201910917313A CN 110535352 B CN110535352 B CN 110535352B
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M3/00—Conversion of dc power input into dc power output
- H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
- H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
- H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
- H02M3/325—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal
- H02M3/335—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only
- H02M3/33507—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of the output voltage or current, e.g. flyback converters
- H02M3/33523—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of the output voltage or current, e.g. flyback converters with galvanic isolation between input and output of both the power stage and the feedback loop
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
- H02M1/0048—Circuits or arrangements for reducing losses
- H02M1/0051—Diode reverse recovery losses
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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
Abstract
The invention provides an isolated DC-DC power supply circuit, and belongs to the field of isolated power supply circuits. The circuit comprises a voltage input end, a primary power control circuit, a transformer, a load circuit and a voltage output end, wherein the voltage input end is connected with a primary winding of the transformer through the primary power control circuit; the voltage input end is used for accessing input voltage; the primary power control circuit is based on a power chip with the model number of NCP3063 as a PWM control generator, excites a primary winding of a transformer to generate voltage change through the on and off of an internally integrated power device, couples out the changed voltage on a secondary winding of the transformer according to the transformation ratio relation of the transformer, and provides the voltage for a load circuit and a voltage output end by the secondary changed voltage. The isolated DC-DC power supply circuit has low cost and small occupied space.
Description
Technical Field
The invention relates to the technology of an isolation power supply circuit, in particular to an isolation DC-DC power supply circuit.
Background
At present, the standard of an LED power supply is updated, the safety requirements of the dimming line needing to be isolated are newly added to the mandatory certification standards of all countries, and the original products need to optimally meet the requirements. Because the circuit adjustment is carried out at the ascending stage of the original circuit, the power supply of the dimming control circuit part needs to be isolated, if the original transformer has no space and is added with a winding, the safety certification of the original product is even not influenced, and the cost and the period of the re-certification of the whole product are saved, at the moment, an isolation DC-DC power supply design method with low cost and small occupied space is needed, the voltage conversion is directly realized from the output voltage of the original circuit, and the requirement of the isolation safety regulation is met.
Disclosure of Invention
The invention aims to provide an isolated DC-DC power supply circuit which is low in cost and small in occupied space.
The invention solves the technical problem, and adopts the technical scheme that: the isolated DC-DC power supply circuit comprises a voltage input end, a primary power control circuit, a transformer, a load circuit and a voltage output end, wherein the voltage input end is connected with a primary winding of the transformer through the primary power control circuit, and a secondary winding of the transformer is connected with the voltage output end through the load circuit;
the voltage input end is used for accessing input voltage;
the primary power control circuit is based on a power chip with the model number of NCP3063 as a PWM control generator, and excites a primary winding of a transformer to generate voltage change through the on and off of an internal integrated power device, the changed voltage is coupled to a secondary winding of the transformer according to the transformation ratio relation of the transformer, and the secondary changed voltage provides voltage for a load circuit and a voltage output end.
Specifically, the primary power control circuit comprises a filter electrolytic capacitor I, a capacitor II, a capacitor III, a resistor II, a TVS tube, a ground wire and a power supply chip with the model number of NCP3063, the positive pole of the filtering electrolytic capacitor is connected with a voltage input end, the negative pole of the filtering electrolytic capacitor is connected with a ground wire, one end of the third capacitor is connected with the voltage input end, the other end of the third capacitor is connected with the ground wire, the input port of an internal reverse comparator of a power chip with the model of NCP3063 and the external timing capacitor port of an internal oscillator are both connected with the ground wire through the second capacitor, the emitting pole of an internal power triode and the power supply negative pole of an internal circuit are both connected with the ground wire, the power supply positive pole of the internal circuit and one end of the second resistor are both connected with the voltage input end, the other ends of the peak current input port and the second resistor are both connected with one end of a primary winding of a transformer, the collector electrode of the internal power triode is connected with the negative pole of a TVS tube, the negative pole of the TVS tube is connected with the ground wire, and the other end of the primary winding of the transformer is connected with the negative pole of the TVS tube.
Further, the clamping pressure value of the TVS tube during working is less than 40V.
The load circuit comprises a first resistor, a first capacitor, a first diode, a second filter electrolytic capacitor and a third resistor, wherein one end of the first resistor and the anode of the first diode are connected with one end of a secondary winding of the transformer, the other end of the first resistor is connected with the cathode of the first diode through the first capacitor, the anode of the second filter electrolytic capacitor is connected with the cathode of the first diode, the cathode of the first filter electrolytic capacitor is connected with a ground wire, one end of the third resistor is connected with the cathode of the first diode, the other end of the third resistor is connected with the ground wire, a voltage output end of the third resistor is connected with the cathode of the first diode, and the other end of the secondary winding of the transformer is connected with the ground wire.
Further, the first diode is a schottky diode, or a diode with a shorter reverse recovery time and a smaller junction capacitance.
Specifically, the turn ratio of the primary winding to the secondary winding of the transformer is related to the magnitude of the output voltage value at the voltage output terminal, where the output voltage value at the voltage output terminal is the input voltage value at the voltage input terminal divided by (the number of turns of the primary winding divided by the number of turns of the secondary winding).
Furthermore, the primary winding of the transformer adopts an enameled wire, and the secondary winding of the transformer adopts a three-layer insulated wire.
Specifically, the working frequency of the power supply chip with the model number of NCP3063 is less than 30 KHz.
Further, the PWM duty ratio of the power supply chip with the model number of NCP3063 is less than 20%.
The isolated DC-DC power supply circuit has the advantages that the power chip with the model number of NCP3063 is used as a PWM control generator, the primary winding of the transformer is excited to generate voltage change through the on and off of the power device integrated inside, the changed voltage is coupled to the secondary winding of the transformer according to the transformation ratio relation of the transformer, the changed voltage of the secondary winding passes through the secondary rectifier diode, the secondary electrolytic capacitor provides voltage for a load after filtering, and the primary winding and the secondary winding are isolated by the transformer to realize circuit isolation.
Drawings
FIG. 1 is a schematic diagram of the circuit structure of the isolated DC-DC power supply circuit of the present invention;
wherein Vin is a voltage input terminal, Vout is a voltage output terminal, GND is a ground, R1 is a first resistor, R2 is a second resistor, R3 is a third resistor, C1 is a first capacitor, C2 is a second capacitor, C3 is a third capacitor, EC1 is a first filter electrolytic capacitor, EC2 is a second filter electrolytic capacitor, D1 is a first diode, ZD1 is a TVS tube, T1 is a transformer, N1 is a primary winding of the transformer, N2 is a secondary winding of the transformer, U1 is a power chip of the model NCP3063, 1 is an internal power triode collector of the power chip of the model NCP3063, 2 is an internal power triode emitter of the power chip of the model NCP3063, 3 is an internal oscillator external timing capacitor port of the power chip of the model NCP3063, 4 is an internal circuit power supply cathode of the power chip of the model NCP3063, 5 is an internal circuit supply cathode of the power chip of the model NCP3063, 6 is an internal circuit input port of the power chip of the model NCP3063, and 7 is a peak current input port of the power supply chip with the model number of NCP 3063.
Detailed Description
The technical scheme of the invention is described in detail in the following with reference to the accompanying drawings.
The isolated DC-DC power supply circuit comprises a voltage input end Vin, a primary power control circuit, a transformer T1, a load circuit and a voltage output end Vout, wherein the voltage input end Vin is connected with a primary winding N1 of a transformer T1 through the primary power control circuit, and a secondary winding N2 of the transformer T1 is connected with the voltage output end Vout through the load circuit.
The circuit structure composition schematic diagram of the circuit is shown in fig. 1, wherein a voltage input end Vin is used for accessing an input voltage; the primary power control circuit is based on a power chip U1 with the model number of NCP3063 as a PWM control generator, and excites the primary winding N1 of the transformer T1 to generate voltage change through the on and off of an internal integrated power device, the changed voltage is coupled on the secondary winding N2 of the transformer T1 according to the transformation ratio relation of the transformer T1, and the secondary changed voltage provides voltage for a load circuit and a voltage output end Vout.
In the circuit, the primary power control circuit comprises a filter electrolytic capacitor EC1, a capacitor II C2, a capacitor III C3, a resistor II R2, a TVS tube ZD1, a ground wire GND and a power chip U1 with the model of NCP3063, wherein the anode of the filter electrolytic capacitor is connected with a voltage input end Vin, the cathode of the filter electrolytic capacitor is connected with the ground wire GND, one end of the capacitor III C3 is connected with the voltage input end Vin, the other end of the capacitor III C853 is connected with the ground wire GND, the internal reverse comparator input port 5 of the power chip U1 with the model of NCP3063 and the internal oscillator external timing capacitor port 3 are both connected with the ground wire GND through the capacitor II C2, the emitter 2 of the internal power triode and the power supply cathode 4 of the internal circuit are both connected with the ground wire GND, one ends of the power supply anode 6 of the internal circuit and the resistor II R2 are both connected with the voltage input end Vin, the peak current input port 7 and the other end of the resistor II R2 are both connected with one end of a primary winding N1 of a transformer T1, the collector 1 of the internal power transistor ZD1 is connected with the cathode of the TVS tube, the negative electrode of the TVS tube ZD1 is connected with the ground GND, and the other end of the primary winding N1 of the transformer T1 is connected with the negative electrode of the TVS tube ZD 1. The clamping pressure value of the TVS pipe ZD1 is less than 40V when the TVS pipe ZD1 works.
The load circuit comprises a first resistor R1, a first capacitor C1, a first diode D1, a second filter electrolytic capacitor EC2 and a third resistor R3, wherein one end of the first resistor R1 and the anode of the first diode D1 are connected with one end of a secondary winding N2 of the transformer T1, the other end of the first resistor R1 is connected with the cathode of the first diode D1 through the first capacitor C1, the anode of the second filter electrolytic capacitor EC2 is connected with the cathode of the first diode D1, the cathode of the second filter electrolytic capacitor EC2 is connected with a ground wire GND, one end of the third resistor R3 is connected with the cathode of the first diode D1, the other end of the third resistor R3 is connected with the ground wire GND, a voltage output end Vout is connected with the cathode of the first diode D1, and the other end of the secondary winding N2 of the transformer T1 is connected with the ground wire GND.
Diode one D1 is a schottky diode, or a diode with a smaller reverse recovery time and a smaller junction capacitance.
The turn ratio of the primary winding N1 and the secondary winding N2 of the transformer T1 is related to the magnitude of the output voltage value of the voltage output terminal Vout, which is the input voltage value of the voltage input terminal Vin ÷ (number of turns of the primary winding N1 ÷ number of turns of the secondary winding N2). The primary winding N1 of the transformer T1 is preferably enameled wire, and the secondary winding N2 is preferably three-layer insulated wire. In order to reduce the power loss of the TVS tube ZD1 and improve the efficiency, the working frequency of the power supply chip U1 with the model number of NCP3063 is less than 30KHz, and the PWM duty ratio of the power supply chip U1 with the model number of NCP3063 is less than 20%.
In a specific application, EC1 is a filter electrolytic capacitor for reducing the Vin voltage fluctuation range. R2 is a current limiting resistor for detecting the value of the transformer primary current. T1 is a transformer, which realizes the transformation of voltage value according to the turn ratio of the primary winding N1 and the secondary winding N2, and simultaneously realizes the circuit isolation due to the isolation of the N1 winding and the N2 winding. ZD1 is TVS tube, provides excitation current release loop for T1, and clamps the N1 winding voltage to protect the U1 internal power switch tube. The C3 filter capacitor provides a high frequency interference loop for the 6 th pin of U1. The C2 capacitor is an external oscillating capacitor set by the U1 working frequency. D1 is the secondary voltage rectifier diode one. The resistor R1 and the capacitor C1 form an RC absorption circuit which is used for absorbing the off peak voltage at two ends of the D1 and damping the peak voltage oscillation at two ends of the D1. The EC2 filter electrolytic capacitors energize the secondary and reduce the ripple of the output voltage. R3 is a dummy load for controlling the voltage fluctuation range of the secondary load when it is no load.
The turn ratio of the winding N1 and the winding N2 of the T1 is related to the magnitude of an output voltage value, Vout is Vin ÷ (N1 ÷ N2), the winding N1 adopts an enameled wire, the winding N2 adopts a three-layer insulated wire, the inductance of the T1 is as large as possible, and the smaller the inductance of the winding N1 is, the better the inductance is when the winding N2 is in a short circuit. R2 determines the magnitude of the load current, and the larger the R2 value is, the smaller the load current value is. The larger the capacitance value of C2, the lower the operating frequency of U1 and the smaller the load carrying capacity of Vout, and in order to reduce ZD2 power loss and improve efficiency, the operating frequency of U1 is controlled to be less than 30KHz, and the PWM duty ratio of U1 is controlled to be less than 20%. ZD1 must be a TVS tube and the clamping pressure value is less than 40V when in work. D1 must employ schottky diodes or diodes with smaller junction capacitance for smaller reverse recovery times.
Therefore, the invention uses non-isolated BUCK or BOOST control power chip NCP3063 as a control unit, secondary voltage feedback is not needed in a peripheral circuit, a traditional optical coupler or a primary bias winding of a transformer is saved, the transformer is designed according to a voltage transformation working mode, a part of loop compensation circuits are not needed to be controlled, the circuit design can be completed by a small number of diodes, resistors and capacitors, primary and secondary isolation is realized by using the transformer, and the voltage transformation is realized to meet the power supply voltage requirement of the circuit.
Claims (7)
1. The isolated DC-DC power supply circuit is characterized by comprising a voltage input end, a primary power control circuit, a transformer, a load circuit and a voltage output end, wherein the voltage input end is connected with a primary winding of the transformer through the primary power control circuit, and a secondary winding of the transformer is connected with the voltage output end through the load circuit;
the voltage input end is used for accessing input voltage;
the primary power control circuit is based on a power chip with the model number of NCP3063 as a PWM control generator, and excites a primary winding of a transformer to generate voltage change through the on and off of an internally integrated power device, the changed voltage is coupled to a secondary winding of the transformer according to the transformation ratio relation of the transformer, and the secondary changed voltage provides voltage for a load circuit and a voltage output end;
the primary power control circuit comprises a filter electrolytic capacitor I, a capacitor II, a capacitor III, a resistor II, a TVS tube, a ground wire and a power supply chip with the model number of NCP3063, the positive electrode of the filtering electrolytic capacitor is connected with a voltage input end, the negative electrode of the filtering electrolytic capacitor is connected with a ground wire, one end of a third capacitor is connected with the voltage input end, the other end of the third capacitor is connected with the ground wire, an input port of an internal reverse comparator of a power supply chip with the model of NCP3063 and an external timing capacitor port of an internal oscillator are both connected with the ground wire through a second capacitor, an emitter of an internal power triode and a power supply negative electrode of an internal circuit are both connected with the ground wire, a power supply positive electrode of the internal circuit and one end of a second resistor are both connected with the voltage input end, the peak current input port and the other end of the second resistor are both connected with one end of a primary winding of a transformer, a collector of the internal power triode is connected with the negative electrode of a TVS (transient voltage suppressor), the positive electrode of the TVS is connected with the ground wire, and the other end of the primary winding of the transformer is connected with the negative electrode of the TVS; the input port of the internal reverse comparator is directly connected with the external timing capacitor port of the internal oscillator;
the load circuit comprises a first resistor, a first capacitor, a diode, a second filter electrolytic capacitor and a third resistor, wherein one end of the first resistor and the anode of the diode are connected with one end of a secondary winding of the transformer, the other end of the first resistor is connected with the cathode of the diode through the first capacitor, the anode of the second filter electrolytic capacitor is connected with the cathode of the diode, the cathode of the second filter electrolytic capacitor is connected with a ground wire, one end of the third resistor is connected with the cathode of the diode, the other end of the third resistor is connected with the ground wire, the voltage output end of the third resistor is connected with the cathode of the diode, and the other end of the secondary winding of the transformer is connected with the ground wire; wherein the third resistor is set as a dummy load.
2. The isolated DC-DC power supply circuit according to claim 1, wherein the clamping voltage value of the TVS tube is less than 40V when in operation.
3. The isolated DC-DC supply circuit of claim 1, wherein the diode is a schottky diode or a diode with a smaller reverse recovery time and a smaller junction capacitance.
4. The isolated DC-DC power supply circuit of claim 1 wherein the turns ratio of the primary winding to the secondary winding of the transformer is related to the magnitude of the output voltage value at the voltage output terminal, wherein the output voltage value at the voltage output terminal is the input voltage value at the voltage input terminal divided by (the number of turns of the primary winding divided by the number of turns of the secondary winding).
5. The isolated DC-DC power supply circuit according to claim 1, wherein the transformer primary winding is enameled and the secondary winding is insulated by three layers.
6. The isolated DC-DC power supply circuit of claim 1, wherein the operating frequency of the power chip model NCP3063 is less than 30 KHz.
7. The isolated DC-DC power supply circuit of claim 1, wherein the PWM duty cycle of the model NCP3063 power chip is less than 20%.
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| Application Number | Priority Date | Filing Date | Title |
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| CN201910917313.6A CN110535352B (en) | 2019-09-26 | 2019-09-26 | Isolated DC-DC power supply circuit |
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| Application Number | Priority Date | Filing Date | Title |
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| CN201910917313.6A CN110535352B (en) | 2019-09-26 | 2019-09-26 | Isolated DC-DC power supply circuit |
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| CN110535352A CN110535352A (en) | 2019-12-03 |
| CN110535352B true CN110535352B (en) | 2022-02-08 |
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| US6021051A (en) * | 1998-12-29 | 2000-02-01 | General Electric Company | Power converter with crowbar circuit and control for very fast output voltage turn-off |
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| CN105577007A (en) * | 2016-03-04 | 2016-05-11 | 杭州士兰微电子股份有限公司 | Primary-side-controlled switch power supply and control method |
| CN108011523A (en) * | 2017-12-07 | 2018-05-08 | 深圳市华星光电技术有限公司 | Circuit of reversed excitation and flyback sourse |
| CN209329963U (en) * | 2019-02-19 | 2019-08-30 | 南宁学院 | A kind of-the 3.3V based on NCP3063~-15V adjustable power circuit |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN201584805U (en) * | 2009-12-17 | 2010-09-15 | 佛山市柏克电力设备有限公司 | Peaceful project monitoring uninterruptible power supply |
| CN202997937U (en) * | 2012-10-26 | 2013-06-12 | 华立仪表集团股份有限公司 | RS485 isolation power supply circuit for electric energy meter |
| CN104660752B (en) * | 2015-03-04 | 2017-06-06 | 西安科技大学 | A kind of emergency communication main frame for having both inside and outside call function |
| CN205792249U (en) * | 2016-06-30 | 2016-12-07 | 华立科技股份有限公司 | Insulating power supply based on PWM chip |
| CN109742953B (en) * | 2018-12-27 | 2021-02-23 | 广州金升阳科技有限公司 | Magnetic isolation driving circuit |
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2019
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Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6021051A (en) * | 1998-12-29 | 2000-02-01 | General Electric Company | Power converter with crowbar circuit and control for very fast output voltage turn-off |
| CN102917512A (en) * | 2012-11-06 | 2013-02-06 | 黄山乾龙电器有限公司 | Method for improving power factor of LED (Light Emitting Diode) power supply circuit |
| CN105577007A (en) * | 2016-03-04 | 2016-05-11 | 杭州士兰微电子股份有限公司 | Primary-side-controlled switch power supply and control method |
| CN108011523A (en) * | 2017-12-07 | 2018-05-08 | 深圳市华星光电技术有限公司 | Circuit of reversed excitation and flyback sourse |
| CN209329963U (en) * | 2019-02-19 | 2019-08-30 | 南宁学院 | A kind of-the 3.3V based on NCP3063~-15V adjustable power circuit |
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| CN110535352A (en) | 2019-12-03 |
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