CN204464968U - Based on the current foldback circuit of thick-film technique, switching power circuit and electronic equipment - Google Patents
Based on the current foldback circuit of thick-film technique, switching power circuit and electronic equipment Download PDFInfo
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- CN204464968U CN204464968U CN201420870603.2U CN201420870603U CN204464968U CN 204464968 U CN204464968 U CN 204464968U CN 201420870603 U CN201420870603 U CN 201420870603U CN 204464968 U CN204464968 U CN 204464968U
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Abstract
The utility model is applicable to field of switch power, and provide a kind of current foldback circuit based on thick-film technique, switching power circuit and electronic equipment, this current foldback circuit comprises: processor, switching tube, electric capacity C7, and palladium-silver conduction band; The input of switching tube is connected with the test side of processor, the control end of switching tube is connected with the regulation output end of processor, the output of switching tube is connected with one end of palladium-silver conduction band, the other end ground connection of palladium-silver conduction band, the power input (VP) of processor is connected supply voltage with voltage input end simultaneously, and the voltage input end of processor is also by electric capacity C7 ground connection.The utility model detects load current by switching tube internal resistance and palladium-silver conduction band; when additionally not increasing current sense resistor; the impedance of regulating circuit is carried out by the number formulary changing palladium-silver conduction band; thus fine adjustment crosses flow point; realize the function of overcurrent protection; reduce circuit volume simultaneously, accord with the demands of the market.
Description
Technical field
The utility model belongs to field of switch power, particularly relates to a kind of current foldback circuit based on thick-film technique, DC/DC switching power circuit and thick-film electronic equipment.
Background technology
Thick film hybrid integrated circuit, on same substrate, make passive network by the thick-film technique such as silk screen printing and sintering, and assemble discrete semiconductor device chip or monolithic integrated circuit or micro element thereon, the hybrid integrated circuit of additional encapsulation again, compared with thin-film hybrid integrated circuit, the design of thick film hybrid integrated circuit is more flexible, simple process, with low cost, and higher voltage, larger power and larger electric current can be tolerated because of it, be particularly suitable for consumer with in the analog switched power supply circuit of industrial electronics.
Usually; based in the DC/DC Switching Power Supply of thick film hybrid integrated circuit technique; need that there is overcurrent protection function; and the mode realizing overcurrent protection is a lot; more employing be that the mode detected by primary current judges overcurrent condition, then control chip turns off the driving of metal-oxide-semiconductor and enters the pattern of hiccup protections.
At present, resistance detection or current transformer is generally adopted to detect for current detecting, but, in current detection circuit, use current sampling resistor or current transformer that power supply product volume can be caused greatly to increase, do not meet the consumption concept that existing market is more and more frivolous to electronic product.
Utility model content
The object of the utility model embodiment is to provide a kind of current foldback circuit based on thick-film technique, is intended to solve adopt resistance detection or current transformer to detect electric current to realize overcurrent protection and cause the problem that thick-film technique small product size is large.
The utility model embodiment is achieved in that a kind of current foldback circuit based on thick-film technique, comprising:
Processor, switching tube, electric capacity C7, and palladium-silver conduction band;
The input of described switching tube is that the test side of described current foldback circuit is connected with the test side (SWN) of described processor, the control end of described switching tube is connected with the regulation output end (NDRV) of described processor, the output of described switching tube is connected with one end of described palladium-silver conduction band, the other end ground connection of described palladium-silver conduction band, the power input (VP) of described processor and voltage input end (VIN) are simultaneously for the power end of described current foldback circuit is connected supply voltage, the voltage input end (VIN) of described processor is also by described electric capacity C7 ground connection, the output that the voltage output end (VOUT) of described processor is described current foldback circuit.
Further, described processor is pulse width modulator.
Further, described switching tube is N-type metal-oxide-semiconductor, and the drain electrode of described N-type metal-oxide-semiconductor is the input of described switching tube, and the source electrode of described N-type metal-oxide-semiconductor is the output of described switching tube, and the grid of described N-type metal-oxide-semiconductor is the control end of described switching tube.
Further, the sheet resistance of described palladium-silver conduction band and number formulary adjustable.
Another object of the utility model embodiment is, provide a kind of DC/DC switching power circuit based on thick-film technique, described switching power circuit comprises:
Transformer T1, rectification unit, filter unit, electric capacity C4, and the above-mentioned current foldback circuit based on thick-film technique;
The different name end of described transformer T1 first coil N1 is that the input of described switching power circuit is by described electric capacity C4 ground connection, the Same Name of Ends of described transformer T1 first coil N1 is connected with the test side of described rectification unit, the Same Name of Ends of described transformer T1 second coil N2 is connected with the input of described rectification unit, the different name end ground connection of described transformer T1 second coil N2, the output of described rectification unit is connected with the input of described filter unit, and the output of described filter unit is the output of described switching power circuit;
The test side of the described current foldback circuit based on thick-film technique is connected with the Same Name of Ends of described transformer T1 first coil N1; the power end of the described current foldback circuit based on thick-film technique is connected with the different name end of described transformer T1 first coil N1, and the output of the described current foldback circuit based on thick-film technique is connected with the output of described rectification unit.
Further, described rectification unit comprises:
Electric capacity C1 and diode D1;
One end of described electric capacity C1 is that the input of described rectification unit is connected with the anode of described diode D1, and the other end of described electric capacity C1 is the test side of described rectification unit, and the negative electrode of described diode D1 is the output of described rectification unit.
Further, described filter unit comprises:
Electric capacity C2 and electric capacity C3;
One end of described electric capacity C2 is input and the output of described filter unit simultaneously, is connected with one end of described electric capacity C3, the other end of described electric capacity C2 and the other end of described electric capacity C3 ground connection simultaneously.
Another object of the utility model embodiment is, provides a kind of thick-film electronic equipment adopting the above-mentioned current foldback circuit based on thick-film technique.
The utility model embodiment detects load current by switching tube internal resistance and palladium-silver conduction band; when additionally not increasing current sense resistor; the impedance of regulating circuit is carried out by the number formulary changing palladium-silver conduction band; thus fine adjustment crosses flow point; realize the function of overcurrent protection; reduce circuit volume simultaneously, accord with the demands of the market.
Accompanying drawing explanation
The structure chart of the current foldback circuit based on thick-film technique that Fig. 1 provides for the utility model embodiment and the DC/DC switching power circuit based on thick-film technique;
The exemplary circuit structure chart of the current foldback circuit based on thick-film technique that Fig. 2 provides for the utility model embodiment and the DC/DC switching power circuit based on thick-film technique.
Embodiment
In order to make the purpose of this utility model, technical scheme and advantage clearly understand, below in conjunction with drawings and Examples, the utility model is further elaborated.Should be appreciated that specific embodiment described herein only in order to explain the utility model, and be not used in restriction the utility model.In addition, if below in described each execution mode of the utility model involved technical characteristic do not form conflict each other and just can mutually combine.
The utility model embodiment detects load current by switching tube internal resistance and palladium-silver conduction band; when additionally not increasing current sense resistor; the impedance of regulating circuit is carried out by the number formulary changing palladium-silver conduction band; thus fine adjustment crosses flow point; realize the function of overcurrent protection; reduce circuit volume simultaneously, accord with the demands of the market.
Below in conjunction with specific embodiment, realization of the present utility model is described in detail:
Fig. 1 shows the structure of the current foldback circuit based on thick-film technique that the utility model embodiment provides and the DC/DC switching power circuit based on thick-film technique, for convenience of explanation, illustrate only the part relevant to the utility model.
As the utility model one embodiment, should can be applied to the DC/DC switching power circuit of any thick-film technique and have in the thick-film electronic equipment of overcurrent protection function, particularly in thick film Switching Power Supply based on the current foldback circuit of thick-film technique.
Should comprise based on the current foldback circuit 1 of thick-film technique:
Processor 11, switching tube 12, electric capacity C7, and palladium-silver conduction band 13;
The input of switching tube 12 is that the test side of current foldback circuit 1 is connected with the test side (SWN) of processor 11, the control end of switching tube 12 is connected with the regulation output end (NDRV) of processor 11, the output of switching tube 12 is connected with one end of palladium-silver conduction band 13, the other end ground connection of palladium-silver conduction band 13, the power input (VP) of processor 11 and voltage input end (VIN) are simultaneously for the power end of current foldback circuit 1 is connected supply voltage, the voltage input end (VIN) of processor 11 is also by electric capacity C7 ground connection, the output that the voltage output end (VOUT) of processor 11 is current foldback circuit 1.
In the utility model embodiment, when switching tube 12 conducting, primary current linearly rises, and the voltage of this test point is detected in the test side (SWN) of processor 11.The duty ratio also corresponding increase of the driving voltage that the increase due to load current can make processor 11 provide, the increase of duty ratio can make again the ON time of switching tube elongated, primary current rises to larger peak current Ip, so the maximum of control load electric current can be carried out by the size controlling former limit peak current Ip, namely cross flow point.
So, when the electric current detected (voltage) is excessive, by the ON time (namely outputing signal duty ratio) of processor 11 by-pass cock pipe 12, thus regulating load electric current is in preset range, thus realizes overcurrent protection.
In the process detecting electric current, the conducting internal resistance of switching tube 12 and palladium-silver conduction band 13 form the effect of current sense resistor.Further, the sheet resistance of palladium-silver conduction band 13 is adjustable, and the test side SWN voltage threshold of processing unit 11 is fixing 0.5V, can also by regulating the mistake flow point of the number formulary regulating circuit of palladium-silver conduction band 13.
As the utility model one embodiment, this palladium-silver conduction band be rectangle or class rectangle there is the certain thickness bianry alloy conductor taking palladium as base and add silver, its resistance characteristic is be conductor resistance between 0.6-0.7um at thickness is 40m Ω/side, the adjustment therefore by regulating the number formulary of palladium-silver conduction band to realize the resistance of palladium-silver conduction band.
The utility model embodiment detects load current by switching tube internal resistance and palladium-silver conduction band; when additionally not increasing current sense resistor; the impedance of regulating circuit is carried out by the number formulary changing palladium-silver conduction band; thus fine adjustment crosses flow point; realize the function of overcurrent protection; reduce circuit volume simultaneously, accord with the demands of the market.
Another object of the utility model embodiment is, provides a kind of DC/DC switching power circuit 2 based on thick-film technique, comprising:
Transformer T1, rectification unit 21, filter unit 22, electric capacity C4, and the current foldback circuit 1 based on thick-film technique in above-described embodiment;
The different name end of transformer T1 first coil N1 is by electric capacity C4 ground connection based on the input of the DC/DC switching power circuit 2 of thick-film technique, the Same Name of Ends of transformer T1 first coil N1 is connected with the test side of rectification unit 21, the Same Name of Ends of transformer T1 second coil N2 is connected with the input of rectification unit 21, the different name end ground connection of transformer T1 second coil N2, the output of rectification unit 21 is connected with the input of filter unit 22, and the output of filter unit 22 is the output of the DC/DC switching power circuit 2 based on thick-film technique;
Test side based on the current foldback circuit 1 of thick-film technique is connected with the Same Name of Ends of transformer T1 first coil N1; power end based on the current foldback circuit 1 of thick-film technique is connected with the different name end of transformer T1 first coil N1, and the output based on the current foldback circuit 1 of thick-film technique is connected with the output of rectification unit 21.
In the utility model embodiment, the course of work of boosting and step-down should be included based on the DC/DC switching power circuit 2 of thick-film technique, adopt SEPIC (single ended primary inductor converter) topological structure, its input voltage nominal value is 5V, in use procedure, input voltage likely changes between 3V-6V, output voltage is 3.3V, full-load current 2A, and crossing flow point is 2.5A-3A.
Processor 11 has current detecting port (SWN); the pressure drop on former limit circuit breaker in middle pipe 12 and palladium-silver conduction band 13 can be detected; if when this pressure drop exceeds the threshold voltage of processor 11 detection port (SWN); processor 11 turns off drive singal; former limit open circuit realizes overcurrent protection; restart subsequently and protect, entering hiccup protections pattern, having less overcurrent power consumption.
The utility model embodiment can finely tune the sheet resistance of palladium-silver conduction band 13 flexibly, such as: the welding conductors etc. by thickening to printing palladium-silver conduction band 13, on palladium-silver conduction band 13, the number formulary can also carrying out mating palladium-silver conductor in conjunction with the conducting internal resistance of switching tube 12 makes resistance adjustable, thus reaches the controlled object of flow point.
So, designing number formulary and the resistance of palladium-silver conduction band 13 with load current 3A, when load current 3A, is 6A by calculating former limit peak current.Processor 11 test side SWN threshold voltage is 0.5V, requires that the all-in resistance of switching tube 12 and palladium-silver conduction band 13 is: 0.5V/6A=83m Ω, and select conducting internal resistance to be the switching tube of 50m Ω, therefore palladium-silver conduction band 13 needs the impedance providing 33m Ω.According to the characteristic of palladium-silver conduction band 40m Ω/side (thickness 0.6 ~ 0.7um), add the palladium-silver conduction band of 1 side in circuit, and suitably thicken, make 1 sheet resistance value slightly be reduced to 33m Ω, to reach designing requirement.
Because extra introducing does not detect resistance; should be very little based on the volume of the DC/DC switching power circuit 2 of thick-film technique; requirement has overcurrent protection function; and flow point is 2.5 ~ 3A excessively; efficiency requirements is higher than 90%; output ripple voltage is less than 30mV (test bandwidth 20MHz), accords with the demands of the market completely.
The utility model embodiment detects load current by switching tube internal resistance and palladium-silver conduction band; when additionally not increasing current sense resistor; the impedance of regulating circuit is carried out by the number formulary changing palladium-silver conduction band; thus fine adjustment crosses flow point; realize the function of overcurrent protection; reduce circuit volume simultaneously, accord with the demands of the market.
Fig. 2 shows the exemplary circuit structure of the current foldback circuit based on thick-film technique that the utility model embodiment provides and the DC/DC switching power circuit based on thick-film technique, for convenience of explanation, illustrate only the part relevant to the utility model.
As the utility model one embodiment, can pulse width modulator U1 be adopted based on the processor 11 in the current foldback circuit 1 of thick-film technique, for the turn-on and turn-off of control switch pipe, regulate duty ratio by feedback control loop.
As the utility model one embodiment, under the precondition that volume allows, the pipe 12 that opens the light should select conducting resistance little as far as possible, the N-type metal-oxide-semiconductor that On current is large, to reduce the conduction loss of switching tube, in order to avoid affect the operating efficiency of power supply.
The drain electrode of this N-type metal-oxide-semiconductor Q1 is the input of switching tube 12, and the source electrode of N-type metal-oxide-semiconductor Q1 is the output of switching tube 12, and the grid of N-type metal-oxide-semiconductor Q1 is the control end of switching tube 12.
The utility model embodiment detects load current by switching tube internal resistance and palladium-silver conduction band; when additionally not increasing current sense resistor; the impedance of regulating circuit is carried out by the number formulary changing palladium-silver conduction band; thus fine adjustment crosses flow point; realize the function of overcurrent protection; reduce circuit volume simultaneously, accord with the demands of the market.
As the utility model one embodiment, can comprise based on the rectification unit 21 in the DC/DC switching power circuit 2 of thick-film technique:
Electric capacity C1 and diode D1;
One end of electric capacity C1 is that the input of rectification unit is connected with the anode of diode D1, and the other end of electric capacity C1 is the test side of rectification unit, and the negative electrode of diode D1 is the output of rectification unit.
Filter unit 22 can comprise:
Electric capacity C2 and electric capacity C3;
One end of electric capacity C2 is input and the output of filter unit simultaneously, is connected with one end of electric capacity C3, the other end of electric capacity C2 and the other end of electric capacity C3 ground connection simultaneously.
Another object of the utility model embodiment is, provides a kind of thick-film resistor equipment adopting the above-mentioned current foldback circuit based on thick-film technique.
The utility model embodiment detects load current by switching tube internal resistance and palladium-silver conduction band; when additionally not increasing current sense resistor; the impedance of regulating circuit is carried out by the number formulary changing palladium-silver conduction band; thus fine adjustment crosses flow point; realize the function of overcurrent protection; reduce circuit volume simultaneously, accord with the demands of the market.
These are only preferred embodiment of the present utility model, not in order to limit the utility model, all do within spirit of the present utility model and principle any amendment, equivalent to replace and improvement etc., all should be included within protection range of the present utility model.
Claims (8)
1. based on a current foldback circuit for thick-film technique, it is characterized in that, described current foldback circuit comprises:
Processor, switching tube, electric capacity C7, and palladium-silver conduction band;
The input of described switching tube is that the test side of described current foldback circuit is connected with the test side (SWN) of described processor, the control end of described switching tube is connected with the regulation output end (NDRV) of described processor, the output of described switching tube is connected with one end of described palladium-silver conduction band, the other end ground connection of described palladium-silver conduction band, the power input (VP) of described processor and voltage input end (VIN) are simultaneously for the power end of described current foldback circuit is connected supply voltage, the voltage input end (VIN) of described processor is also by described electric capacity C7 ground connection, the output that the voltage output end (VOUT) of described processor is described current foldback circuit.
2. current foldback circuit as claimed in claim 1, it is characterized in that, described processor is pulse width modulator.
3. current foldback circuit as claimed in claim 1; it is characterized in that; described switching tube is N-type metal-oxide-semiconductor; the drain electrode of described N-type metal-oxide-semiconductor is the input of described switching tube; the source electrode of described N-type metal-oxide-semiconductor is the output of described switching tube, and the grid of described N-type metal-oxide-semiconductor is the control end of described switching tube.
4. current foldback circuit as claimed in claim 1, it is characterized in that, sheet resistance and the number formulary of described palladium-silver conduction band are adjustable.
5. based on a switching power circuit for thick-film technique, it is characterized in that, described switching power circuit comprises:
Transformer T1, rectification unit, filter unit, electric capacity C4, and the current foldback circuit based on thick-film technique as described in any one of Claims 1-4;
The different name end of described transformer T1 first coil N1 is that the input of described switching power circuit is by described electric capacity C4 ground connection, the Same Name of Ends of described transformer T1 first coil N1 is connected with the test side of described rectification unit, the Same Name of Ends of described transformer T1 second coil N2 is connected with the input of described rectification unit, the different name end ground connection of described transformer T1 second coil N2, the output of described rectification unit is connected with the input of described filter unit, and the output of described filter unit is the output of described switching power circuit;
The test side of the described current foldback circuit based on thick-film technique is connected with the Same Name of Ends of described transformer T1 first coil N1; the power end of the described current foldback circuit based on thick-film technique is connected with the different name end of described transformer T1 first coil N1, and the output of the described current foldback circuit based on thick-film technique is connected with the output of described rectification unit.
6. switching power circuit as claimed in claim 5, it is characterized in that, described rectification unit comprises:
Electric capacity C1 and diode D1;
One end of described electric capacity C1 is that the input of described rectification unit is connected with the anode of described diode D1, and the other end of described electric capacity C1 is the test side of described rectification unit, and the negative electrode of described diode D1 is the output of described rectification unit.
7. switching power circuit as claimed in claim 5, it is characterized in that, described filter unit comprises:
Electric capacity C2 and electric capacity C3;
One end of described electric capacity C2 is input and the output of described filter unit simultaneously, is connected with one end of described electric capacity C3, the other end of described electric capacity C2 and the other end of described electric capacity C3 ground connection simultaneously.
8. an electronic equipment, is characterized in that, described electronic equipment comprises the current foldback circuit based on thick-film technique as described in any one of Claims 1-4.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420870603.2U CN204464968U (en) | 2014-12-31 | 2014-12-31 | Based on the current foldback circuit of thick-film technique, switching power circuit and electronic equipment |
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| Application Number | Priority Date | Filing Date | Title |
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| CN201420870603.2U CN204464968U (en) | 2014-12-31 | 2014-12-31 | Based on the current foldback circuit of thick-film technique, switching power circuit and electronic equipment |
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| CN204464968U true CN204464968U (en) | 2015-07-08 |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106370912A (en) * | 2016-08-18 | 2017-02-01 | 李鹏 | Method, system and motor-driving system for improving MOSFET tube current sampling accuracy |
| CN109845083A (en) * | 2016-10-12 | 2019-06-04 | 日立汽车系统株式会社 | Power inverter and the system for using the device |
-
2014
- 2014-12-31 CN CN201420870603.2U patent/CN204464968U/en active Active
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106370912A (en) * | 2016-08-18 | 2017-02-01 | 李鹏 | Method, system and motor-driving system for improving MOSFET tube current sampling accuracy |
| CN106370912B (en) * | 2016-08-18 | 2020-02-11 | 李鹏 | Method and system for improving current sampling precision of MOSFET (metal oxide semiconductor field effect transistor) tube and motor driving system |
| CN109845083A (en) * | 2016-10-12 | 2019-06-04 | 日立汽车系统株式会社 | Power inverter and the system for using the device |
| CN109845083B (en) * | 2016-10-12 | 2021-10-22 | 日立安斯泰莫株式会社 | Power conversion device and power conversion system using the same |
| US11171576B2 (en) | 2016-10-12 | 2021-11-09 | Hitachi Astemo, Ltd. | Power conversion device and system using the same |
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