CN202798461U - Application circuit of switching power supply control chip - Google Patents
Application circuit of switching power supply control chip Download PDFInfo
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- CN202798461U CN202798461U CN201220468336.7U CN201220468336U CN202798461U CN 202798461 U CN202798461 U CN 202798461U CN 201220468336 U CN201220468336 U CN 201220468336U CN 202798461 U CN202798461 U CN 202798461U
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- control chip
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Abstract
The utility model provides an application circuit of a switching power supply control chip. The application circuit comprises the switching power supply control chip, a starting circuit, a rectifying circuit, a switching circuit, a transformer, a filter circuit and a feedback circuit, wherein the starting circuit is connected with the switching power supply control chip, the rectifying circuit is connected with the starting circuit, the switching circuit is connected with the switching power supply control chip, the transformer is connected with the switching circuit, the filter circuit is connected with the transformer, and the power supply control chip comprises a ground pin, a power pin, a direct current output pin and a feedback voltage pin. Compared with the prior art, the application circuit has the advantages that the internal module structure and the external application circuit of the switching power supply control chip are changed, so that the conversion from alternating current to direct current can be achieved through the ground pin, the power pin, the direct current output pin and the feedback voltage pin only, the manufacturing cost is effectively reduced, the structure is applicable to T092 type packaging, the packaging process is further simplified, and the application circuit is beneficial to wide application of the switching power supply control chip.
Description
Technical field
The invention belongs to integrated circuit fields, relate in particular to a kind of Switching Power Supply control chip application circuit.
Background technology
At present, traditional Switching Power Supply control chip adopts five pin SOT23(Small Outline Transistor usually, small outline transistor) formula encapsulation, as shown in Figure 1, for the Switching Power Supply control chip diagram of existing five pin encapsulation, comprising grounding pin 11, power pins 12, direct current output pin 13, feedback voltage pin 14, input pin 15, constant voltage loop unit 16, modulating unit 17, reference cell 18 and comparing unit 19.Fig. 2 is the application circuit of the Switching Power Supply control chip of prior art five pin encapsulation, wherein, includes Switching Power Supply control chip 1, current rectifying and wave filtering circuit 21, start-up circuit 22, switching circuit 23, transformer 24, feedback circuit 25 and filter circuit 26.
The input of current rectifying and wave filtering circuit 21 connects AC power, the output of current rectifying and wave filtering circuit 21 is connected with the input of start-up circuit 22, the output of start-up circuit 22 is connected with the outside link of the power pins 12 of Switching Power Supply control chip 1, the input of switching circuit 23 is connected with the outside link of Switching Power Supply control chip 1 direct current output pin 13, the sampling end of switching circuit 23 is connected with the outside link of the input pin 15 of Switching Power Supply control chip 1, the earth terminal of switching circuit 23 is connected with the outside link of the grounding pin of Switching Power Supply control chip 1, common ground, the output of switching circuit 23 is connected with the armature winding of transformer 24, the auxiliary winding of transformer 24 is connected with the input of feedback circuit 25, the output of feedback circuit 25 is connected with the outside link of the feedback voltage pin 14 of Switching Power Supply control chip 1, the secondary winding of transformer 24 is connected with the input of filter circuit 26, and the output of filter circuit 26 is the output of application circuit of the Switching Power Supply control chip 1 of this five pin encapsulation.
AC power is through becoming the direct current of concussion high pressure behind the current rectifying and wave filtering circuit 21, this high voltage direct current is by charging with bootrom 1 to start-up circuit, make the direct current output pin 13 output low-voltage DCs of chip 1, this low-voltage DC is exported to the armature winding of transformer 24 by switch element 23, by secondary winding this voltage is passed to filter circuit 26, is undertaken becoming this application circuit output voltage behind the secondary filtering by 26 pairs of these low-voltage DCs of filter circuit.
Because the structure of five pins (11,12,13,14,15) of above-mentioned Switching Power Supply control chip is so that this chip can only be selected the encapsulation of SOT23 formula at present, still, SOT23 formula packaging technology is complicated, and cost is high, is unfavorable for the extensive use of Switching Power Supply control chip.
Summary of the invention
The purpose of this utility model is to provide a kind of Switching Power Supply control chip application circuit, is intended to solve the Switching Power Supply control chip application cost of manufacture height of existing five leg structures, the problem of packaging technology complexity.
For achieving the above object, technical scheme of the present invention is:
A kind of Switching Power Supply control chip application circuit, include the start-up circuit of Switching Power Supply control chip, connecting valve power supply control chip, rectification circuit, the switching circuit of connecting valve power supply control chip, the transformer of connecting valve circuit and the filter circuit of connection transformer of connection start-up circuit, wherein, described application circuit also includes feedback circuit; Described power supply control chip includes grounding pin, power pins, direct current output pin and feedback voltage pin; Described power pins connects start-up circuit, and described feedback pin connects feedback circuit, and described direct current output pin connecting valve circuit.
Further, described feedback circuit also is connected to respectively start-up circuit and transformer.
Further, the output of described start-up circuit is connected with the bringing-out of described power pins, is used for charging when power supply electrifying, to described chip output starting resistor; The input of described switching circuit is connected with the outside link of described direct current output pin, and the outside link common ground of the earth terminal of described switching circuit and described grounding pin.
Further, the Same Name of Ends of the armature winding N1 of described transformer T1 is connected with the input of described start-up circuit, the different name end of described armature winding N1 is connected with the output of described switching circuit, the Same Name of Ends of the secondary winding N2 of described transformer T1 is the output negative pole of described application circuit, the different name end of the secondary winding N2 of described transformer T1 is connected with the input of described filter circuit, and the Same Name of Ends of the compole winding N3 of described transformer T1 is connected with described grounding pin.
Further, the input of described feedback circuit is connected with the different name end of the auxiliary winding N3 of described transformer T1, be used for receiving the compole feedback voltage signal, the first output of described feedback circuit is connected with the bringing-out of described power pins, be used for described power pins is carried out supply power voltage, the second output of described feedback circuit is connected with the bringing-out of described feedback voltage pin, be used for providing feedback voltage signal, the earth terminal of described feedback circuit is connected with described grounding pin.
Further, the positive input terminal of described filter circuit is connected with the different name end of the secondary winding N2 of described transformer T1, the negative input end of described filter circuit is connected with the Same Name of Ends of the secondary winding N2 of described transformer T1, the positive output end of described filter circuit is the output cathode of described application circuit, and the negative output terminal of described filter circuit is the output negative pole of described application circuit.
Further, described feedback circuit includes diode D6, the 5th resistance R 5 and the 6th resistance R 6; The anode of described diode D6 is the input of described feedback circuit, one end of the negative electrode of described diode D6 and the 5th resistance R 5 is connected to the first output of described feedback circuit, described the 5th resistance R 5 is connected with the 6th resistance R 6, and the intermediate connection point of the 5th resistance R 5 and the 6th R6 is the second output of described feedback circuit, and the other end of described the 6th resistance R 6 is the earth terminal of described feedback circuit
Compared to prior art, this creation is by changing Switching Power Supply control chip internal module structure and applications circuit, so that only can realize that by power pins, grounding pin, direct current output pin and feedback voltage pin alternating current arrives galvanic conversion, effectively reduce cost of manufacture, and this structure is applicable to the encapsulation of TO92 formula, further simplify packaging technology, be conducive to the extensive use of Switching Power Supply control chip.
Description of drawings
Fig. 1 is the structure chart of the Switching Power Supply control chip of existing five pin encapsulation;
Fig. 2 is the Switching Power Supply control chip application circuit theory diagram of existing five pin encapsulation;
Fig. 3 is the structure chart of Switching Power Supply control chip of the present utility model;
Fig. 4 is the theory diagram of Switching Power Supply control chip application circuit of the present utility model;
Fig. 5 is the circuit diagram of the utility model Switching Power Supply control chip application circuit.
Embodiment
For purpose, technical scheme and advantage that the present invention is created is clearer, below in conjunction with drawings and Examples, the present invention's creation is further elaborated.Should be appreciated that specific embodiment described herein is only in order to explain that the present invention creates, and is not intended to limit the present invention creation.
Please refer to shown in Figure 3, Fig. 3 illustrates the structure of the Switching Power Supply control chip of the present invention's creation, this Switching Power Supply control chip 3 includes reference cell 37, modulating unit 36, constant voltage loop unit 35, comparing unit 38 and grounding pin 31, power pins 32, direct current output pin 33, feedback voltage pin 34, wherein, described grounding pin 31 is drawn chip with the chip internal earth terminal, be connected with ground wire, behind the alternating voltage process rectifying and wave-filtering of input, form the high-voltage dc signal of concussion, this high-voltage dc signal is inputted by power pins 32 as the starting resistor of Switching Power Supply control chip 3, and Switching Power Supply control chip 3 is started working after power pins is increased to certain value.Described direct current output pin 33 is used for the output low-voltage dc voltage, and with this low-voltage dc voltage as sampled signal input switch power supply control chip 3; Described feedback voltage pin 34 is used for to described Switching Power Supply control chip input feedback voltage signal; The input of described constant voltage loop unit 35 is connected with the inside link of feedback voltage pin 34, the output of constant voltage loop unit 35 is connected with the input of modulating unit 36, for detection of feedback voltage signal, and adjust the operating state of modulating unit 36 according to feedback signal; And the first input end of described comparing unit 38 is connected with the output of reference cell 37, the second input of comparing unit 38 is connected with the inside link of direct current output pin 33, the output of comparing unit 38 is connected with the input of modulating unit 36, be used for reference voltage that sampled signal and reference cell 37 are provided relatively, modulating unit 36 is exported comparison control signals.
Described constant voltage loop unit 35 detects the voltage feedback signal of Voltage Feedback pin 34, work in different states according to different voltage feedback signal control modulating units 36, when voltage feedback signal during greater than preset value, the higher voltage of constant voltage loop unit 35 outputs, make modulating unit 36 reduce the duty ratio of modulation signal, and then reduce the amplitude of output dc voltage, when voltage feedback signal during less than preset value, the lower voltage of constant voltage loop unit 35 outputs, make modulating unit 36 increase the duty ratio of modulation signal, and then the amplitude of increase output dc voltage, with stablizing of control output dc voltage amplitude.
Described comparing unit 38 detects the crest voltage of direct current output pin 33, when the crest voltage of direct current output pin 33 during greater than reference voltage value, comparing unit 38 output low levels, modulating unit 36 is closed, when the crest voltage of direct current output pin 33 during less than reference voltage value, comparing unit 38 output low levels are opened modulating unit 36, can control the stable of output DC stream amplitude by such on-off mode.
Please refer to shown in Figure 4ly, Fig. 4 is the structure of this creation Switching Power Supply control chip application circuit, and it includes rectification circuit 41, filter capacitor C1, start-up circuit 42, switching circuit 43, transformer T1, feedback circuit 45 and filter circuit 46.
Wherein, the input of described start-up circuit 42 is connected with the end of filter capacitor C1, and the output of start-up circuit 42 is connected with the bringing-out of power pins 12, is used for charging when power supply electrifying, to chip 3 output starting resistors; The input of described switching circuit 43 is connected with the outside link of direct current output pin 33, and the outside link common ground of the earth terminal of switching circuit 43 and grounding pin 31 is used for conducting when chip 3 output low-voltage dc voltage, the output On current; The Same Name of Ends of the armature winding N1 of described transformer T1 is connected with the input of start-up circuit 42, the different name end of armature winding N1 is connected with the output of switching circuit 43, the Same Name of Ends of the secondary winding N2 of transformer T1 is the output negative pole of the application circuit 4 of Switching Power Supply control chip, the different name end of the secondary winding N2 of transformer T1 is connected with the input of filter circuit 46, is used for On current is converted to output voltage; The input of described feedback circuit 45 is connected with the different name end of the auxiliary winding N3 of transformer T1, be used for receiving the compole feedback voltage signal, the first output of feedback circuit 45 is connected with the bringing-out of power pins 32, be used for power pins 32 is carried out supply power voltage, the second output of feedback circuit 45 is connected with the bringing-out of feedback voltage pin 34, be used for providing feedback voltage signal, the earth terminal of feedback circuit 45 is connected with grounding pin 31; The positive input terminal of described filter circuit 46 is connected with the different name end of the secondary winding N2 of transformer T1, the negative input end of filter circuit 46 is connected with the Same Name of Ends of the secondary winding N2 of transformer T1, the positive output end of filter circuit 46 is the output cathode of the application circuit of Switching Power Supply control chip, the negative output terminal of filter circuit 46 is the output negative pole of the application circuit of Switching Power Supply control chip, for reducing the ripple in the low pressure concussion direct voltage of sensing.
Please refer to shown in Figure 5ly, Fig. 5 is the circuit diagram of this creation Switching Power Supply control chip application circuit.
Wherein, start-up circuit 42 includes resistance R 1 and capacitor C 3, and an end of resistance R 1 is the input of start-up circuit 42, and the other end of resistance R 1 is connected with an end of capacitor C 3, and its link is the output of start-up circuit 42, the other end ground connection of capacitor C 3.
In the present embodiment, AC power becomes the high voltage direct current of concussion by 3 chargings of 1 pair of capacitor C of resistance R after through the rectification circuit 41 that is made of rectifier bridge and filter capacitor C1, when the voltage on the capacitor C 3 reaches the starting resistor of chip 3, chip 3 is started working, constant voltage loop unit 35 detects the voltage feedback signal of Voltage Feedback pin 34, work in different states according to different voltage feedback signal control modulating units 36, when voltage feedback signal during greater than preset value, the higher voltage of constant voltage loop unit 35 outputs, make modulating unit 36 reduce the duty ratio of modulation signal, and then reduce the amplitude of output dc voltage, when voltage feedback signal during less than preset value, the lower voltage of constant voltage loop unit 35 outputs, make modulating unit 36 increase the duty ratio of modulation signal, and then the amplitude of increase output dc voltage, with stablizing of control output dc voltage amplitude.
Comparing unit 38 detects the crest voltage of direct current output pin 33, when the crest voltage of direct current output pin 33 during greater than reference voltage value, comparing unit 38 output low levels, modulating unit 36 is closed, when the crest voltage of direct current output pin 33 during less than reference voltage value, comparing unit 38 output low levels are opened modulating unit 36, can control the stable of output DC stream amplitude by such on-off mode.
The present invention's creation only can realize that by power pins, grounding pin, direct current output pin and feedback voltage pin alternating current arrives galvanic conversion, effectively reduce cost of manufacture, and this structure is applicable to the encapsulation of TO92 formula, further simplify packaging technology, be conducive to the extensive use of Switching Power Supply control chip.
The above only is preferred embodiment of the present invention, not in order to limiting the present invention, all any modifications of doing within the spirit and principles in the present invention, is equal to and replaces and improvement etc., all should be included within protection scope of the present invention.
Claims (7)
1. Switching Power Supply control chip application circuit, include the start-up circuit of Switching Power Supply control chip, connecting valve power supply control chip, rectification circuit, the switching circuit of connecting valve power supply control chip, the transformer of connecting valve circuit and the filter circuit of connection transformer of connection start-up circuit, it is characterized in that: described application circuit also includes feedback circuit; Wherein, described power supply control chip includes grounding pin, power pins, direct current output pin and feedback voltage pin; Described power pins connects start-up circuit, and described feedback pin connects feedback circuit, and described direct current output pin connecting valve circuit.
2. Switching Power Supply control chip application circuit as claimed in claim 1 is characterized in that, described feedback circuit also is connected to respectively start-up circuit and transformer.
3. Switching Power Supply control chip application circuit as claimed in claim 2, it is characterized in that: the output of described start-up circuit is connected with the bringing-out of described power pins, is used for charging when power supply electrifying, to described chip output starting resistor; The input of described switching circuit is connected with the outside link of described direct current output pin, and the outside link common ground of the earth terminal of described switching circuit and described grounding pin.
4. Switching Power Supply control chip application circuit as claimed in claim 3, it is characterized in that: the Same Name of Ends of the armature winding (N1) of described transformer (T1) is connected with the input of described start-up circuit, the different name end of described armature winding (N1) is connected with the output of described switching circuit, the Same Name of Ends of the secondary winding (N2) of described transformer (T1) is the output negative pole of described application circuit, the different name end of the secondary winding (N2) of described transformer (T1) is connected with the input of described filter circuit, and the Same Name of Ends of the compole winding (N3) of described transformer (T1) is connected with described grounding pin.
5. Switching Power Supply control chip application circuit as claimed in claim 4, it is characterized in that: the input of described feedback circuit is connected with the different name end of the auxiliary winding (N3) of described transformer (T1), be used for receiving the compole feedback voltage signal, the first output of described feedback circuit is connected with the bringing-out of described power pins, be used for described power pins is carried out supply power voltage, the second output of described feedback circuit is connected with the bringing-out of described feedback voltage pin, be used for providing feedback voltage signal, the earth terminal of described feedback circuit is connected with described grounding pin.
6. Switching Power Supply control chip application circuit as claimed in claim 5, it is characterized in that: the positive input terminal of described filter circuit is connected with the different name end of the secondary winding (N2) of described transformer (T1), the negative input end of described filter circuit is connected with the Same Name of Ends of the secondary winding (N2) of described transformer (T1), the positive output end of described filter circuit is the output cathode of described application circuit, and the negative output terminal of described filter circuit is the output negative pole of described application circuit.
7. Switching Power Supply control chip application circuit as claimed in claim 6, it is characterized in that: described feedback circuit includes diode (D6), the 5th resistance (R5) and the 6th resistance (R6);
The anode of described diode (D6) is the input of described feedback circuit, one end of the negative electrode of described diode (D6) and the 5th resistance (R5) is connected to the first output of described feedback circuit, described the 5th resistance (R5) is connected with the 6th resistance (R6), and the 5th resistance (R5) is the second output of described feedback circuit with the intermediate connection point of the 6th (R6), and the other end of described the 6th resistance (R6) is the earth terminal of described feedback circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201220468336.7U CN202798461U (en) | 2012-09-14 | 2012-09-14 | Application circuit of switching power supply control chip |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201220468336.7U CN202798461U (en) | 2012-09-14 | 2012-09-14 | Application circuit of switching power supply control chip |
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| Publication Number | Publication Date |
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| CN202798461U true CN202798461U (en) | 2013-03-13 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201220468336.7U Expired - Lifetime CN202798461U (en) | 2012-09-14 | 2012-09-14 | Application circuit of switching power supply control chip |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TWI479784B (en) * | 2013-03-18 | 2015-04-01 | Power Forest Technology Corp | Ac/dc converting circuit |
-
2012
- 2012-09-14 CN CN201220468336.7U patent/CN202798461U/en not_active Expired - Lifetime
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TWI479784B (en) * | 2013-03-18 | 2015-04-01 | Power Forest Technology Corp | Ac/dc converting circuit |
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Legal Events
| Date | Code | Title | Description |
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| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C56 | Change in the name or address of the patentee |
Owner name: SHENZHEN FUMAN ELECTRONICS GROUP CO., LTD. Free format text: FORMER NAME: SHENZHEN FINE MADE ELECTRONICS CO., LTD. |
|
| CP03 | Change of name, title or address |
Address after: 518000 Guangdong city of Shenzhen province Tian Futian District Shennan Road, Che Kung Temple Industrial Zone digital city Times Building building 2403A-1 Patentee after: FINE MADE MICROELECTRONICS GROUP CO.,LTD. Address before: 10 building 518057 unit B5-B6 in Guangdong Province, Shenzhen city Nanshan District South Road four No. 31 EVOC Technology Building Patentee before: SHENZHEN FUMAN ELECTRONIC Co.,Ltd. |
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| CX01 | Expiry of patent term |
Granted publication date: 20130313 |
|
| CX01 | Expiry of patent term |