CN201821412U - Video operational amplifier circuit and set-top box provided with same - Google Patents
Video operational amplifier circuit and set-top box provided with same Download PDFInfo
- Publication number
- CN201821412U CN201821412U CN 201020599797 CN201020599797U CN201821412U CN 201821412 U CN201821412 U CN 201821412U CN 201020599797 CN201020599797 CN 201020599797 CN 201020599797 U CN201020599797 U CN 201020599797U CN 201821412 U CN201821412 U CN 201821412U
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- video
- resistance
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- top box
- video driver
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Abstract
The utility model discloses a video operational amplifier circuit and a set-top box provided with the circuit. The video operational amplifier circuit comprises a video driver; a video input signal is received by an input terminal of the video driver, operated and amplified, and then output through an output terminal of the video driver; a first resistor used for regulating the amplitude of the video signal is connected between the input terminal of the video driver and the ground; and a second resistor used for conducting impedance matching is connected in series with the output terminal of the driver. The video operational amplifier circuit disclosed by the utility model is structured by adopting one video driver matched with two resistors, has a simple circuit structure, performs the functions of a video operational amplifier, saves the space of a circuit board, improves the load-bearing capability of the circuit and the reliability of a system, reduces the hardware cost, and is particularly suitable for being popularized and applied to the circuit design of household electrical appliances, such as digital television sets, the set-top boxes, and the like, so as to improve the overall performance of products.
Description
Technical field
The utility model belongs to the video processing circuit technical field, specifically, relates to a kind of set-top box that vision signal is carried out the video discharge circuit of processing and amplifying and adopted described video discharge circuit design.
Background technology
In the digital television techniques field, particularly in the circuit design of present top box of digital machine, because the decoding device output current in its internal circuit is less, the load capacity deficiency, if the vision signal of its decoding output directly is passed to back level television set, tend to cause the vision signal instability, influence the normal problem that shows of TV signal and occur.In order to address this problem, need set up one-level video discharge circuit in the VT of decoding device, to improve the stability of video signal transmission.
The main effect of video discharge circuit is exactly to remedy the decoding shortcoming that device output current is little, load capacity is not enough.Simultaneously, the influence that late-class circuit causes front stage circuits be can also reduce, thereby the carrying load ability of intensifier circuit and the purpose of front and back level impedance matching reached by setting up the video discharge circuit.
The video discharge circuit that present top box of digital machine, its inside adopt is built by discrete components and parts such as triode, resistance, electric capacity and inductance usually.A kind of existing set-top box video discharge circuit has as shown in Figure 1 adopted 3 triodes and some resistance, electric capacity to set up and form, and by debugging the concrete parameter value of each related device, can carry out the suitable adjustment of video index.
Adopt the video discharge circuit of this traditional structure mainly to have tripartite planar defect: the one, the employed device of system is more, need take the bigger circuit board space of set-top box; The 2nd, because circuit devcie is more, the debugging of video index is difficult, and conformity of production is poor, and stability is not high; The 3rd, the existing difference of each device can cause the fluctuation of net cast bigger, thereby has influenced the watching quality of video frequency program.
Based on above reason, how researching and developing a kind of service behaviour height, taking little and video discharge circuit good reliability in PCB space is a subject matter to be solved in the utility model.
The utility model content
The existing existing use device of video discharge circuit is many, the problem of poor work stability in order to solve for the utility model, and a kind of video discharge circuit simple in structure is provided, and has saved the PCB space, has improved the output quality of vision signal.
For addressing the above problem, the utility model is achieved by the following technical solutions:
A kind of video discharge circuit comprises a video driver, the input terminal receiver, video input signal of described video driver, carry out the computing processing and amplifying after, by the output of its lead-out terminal; Between the input terminal of described video driver and ground, be connected with first resistance that is used to adjust video amplitude; On the lead-out terminal of described video driver, be in series with second resistance that is used to carry out impedance matching.
Further, the input terminal of described video driver connects decoder, the video input signals of Rcv decoder output.
Further again, described first resistance preferably adopts variable resistance, can be to adjusting by the video amplitude of video driver output by changing its resistance.。
Preferably, the resistance of described second resistance is 75 ohm, is used for the coupling of late-class circuit.
Further again, described video driver is an integrated transporting discharging chip, its power supply terminal connection+5V DC power supply.
Based on above-mentioned video discharge circuit structure, the utility model provides a kind of set-top box that adopts described video discharge circuit design again, comprises being used for the TV signal that receives is carried out the decoder of decoding processing and the video driver that is connected with described decoder.Wherein, the input terminal of described video driver connects decoder, and the vision signal of Rcv decoder output is after the row operation processing and amplifying of going forward side by side, by the lead-out terminal output of video driver; Between the input terminal of described video driver and ground, be connected with first resistance that is used to adjust video amplitude; On the lead-out terminal of described video driver, be in series with second resistance that is used to carry out impedance matching.
Further, the lead-out terminal of described video driver transfers to back level television set with the vision signal after the processing and amplifying by AV terminal, to realize displaying the play of TV programme by the AV terminal of the second resistance junctor top box.
Compared with prior art, advantage of the present utility model and good effect are: video discharge circuit of the present utility model adopts a video driver to cooperate two resistance to make up and forms, circuit structure is simple, when realizing video amplifier function, save circuit board space, improved the load capacity of circuit and the reliability of system, reduced hardware cost, be particluarly suitable for promoting the use of in the circuit design of household appliances such as digital television or set-top box, to improve the complete machine performance of product.
After reading the detailed description of the utility model execution mode in conjunction with the accompanying drawings, other characteristics of the present utility model and advantage will become clearer.
Description of drawings
Fig. 1 is the schematic diagram of conventional video discharge circuit;
Fig. 2 is the circuit theory diagrams of a kind of embodiment of the video discharge circuit that proposes of the utility model.
Embodiment
Below in conjunction with accompanying drawing embodiment of the present utility model is described in detail.
To adopt discrete component to build the use component number that is caused many in order to solve existing video discharge circuit for the utility model, it is big to take the PCB space, and video index debug difficulties, the problem of conformity of production difference, having proposed a kind of needs to adopt a video driver to cooperate two resistance can realize video discharge circuit to the vision signal processing and amplifying, and compact conformation has good load capacity, the debugging of video index is simple, and stability is strong.
Be example below with the top box of digital machine, elaborate the concrete establishment structure and the operation principle thereof of described video discharge circuit by a specific embodiment.
Embodiment one, referring to shown in Figure 2, the integrated transporting discharging chip that it is SGM9111 that the video driver N01 of present embodiment can adopt a model is realized, input terminal 3 pin receiver, video input signal CVBSIN by video driver N01, after video driver N01 carries out the computing processing and amplifying, increase the output current of vision signal, and then by its lead-out terminal 4 pin output, to improve the load capacity of video output signals CVBSOUT.In top box of digital machine, described video input signals CVBSIN can specifically refer to the vision signal of the encoder output by set-top box inside, such as Composite Video Broadcast Signal CVBS etc.
For the video index is realized regulating, input terminal 3 pin of described video driver N01 are by first resistance R, 1 ground connection.Described first resistance R 1 is used for the amplitude of the vision signal CVBSOUT that exports by video driver N01 is adjusted.For the set-top box of concrete model, can select the fixed resistance R1 of suitable resistance to carry out circuit design; And in order to improve the adaptability of described video discharge circuit, described first resistance R, the 1 preferred variable resistance that adopts carries out circuit design, according to dissimilar set-top box circuit, regulate the resistance of variable resistance R1, make the amplitude of the vision signal CVBSOUT that adjusts output satisfy index request.
In order to realize the impedance matching of front stage circuits and late-class circuit, present embodiment also further is in series with second resistance R 2 on lead-out terminal 4 pin of described video driver N01, as shown in Figure 2.By selecting second resistance R 2 of suitable resistance, can reduce the influence of late-class circuit to front stage circuits.For top box of digital machine, it is that 75 ohm fixed resistance carries out circuit design that described second resistance R 2 can be selected resistance, is connected between the AV terminal of lead-out terminal 4 pin of video driver N01 and set-top box, to reach the purpose that is complementary with back-end circuit.
The 1st pin of described video driver N01 and the 2nd pin are earth terminal, in the junctor top box circuit board systematically; The 5th pin is the power supply terminal VCC of video driver N01, connection+5V DC power supply 5VAS, and N01 provides operating voltage for video driver.Described+5V DC power supply 5VAS can specifically be provided by the output of the power module in the set-top box internal circuit.
The video discharge circuit of present embodiment adopts video driver to carry out circuit design, can carry out processing and amplifying to the single channel vision signal in the top box of digital machine, vision signal by this video discharge circuit output not only has good load capacity, and the debugging of video index is simple, has electrostatic-proof function, when improving the complete machine performance, reduced cost, improved competition capability.
Certainly, video discharge circuit that present embodiment proposed is set up structure and is gone for digital television etc. equally and need carry out in the circuit design of electronic product of video decode output, present embodiment be not limited in above for example.
The above only is preferred embodiment of the present utility model, is not to be to restriction of the present utility model, and any those skilled in the art may utilize the technology contents of above-mentioned announcement to be changed or be modified as the equivalent embodiment of equivalent variations.But every technical solutions of the utility model content that do not break away to any simple modification, equivalent variations and remodeling that above embodiment did, still belongs to the protection range of technical solutions of the utility model according to technical spirit of the present utility model.
Claims (10)
1. video discharge circuit is characterized in that: comprise a video driver, the input terminal receiver, video input signal of described video driver, carry out the computing processing and amplifying after, by its lead-out terminal output; Between the input terminal of described video driver and ground, be connected with first resistance that is used to adjust video amplitude; On the lead-out terminal of described video driver, be in series with second resistance that is used to carry out impedance matching.
2. video discharge circuit according to claim 1 is characterized in that: the input terminal of described video driver connects decoder, the video input signals of Rcv decoder output.
3. video discharge circuit according to claim 1 is characterized in that: described first resistance is variable resistance.
4. video discharge circuit according to claim 1 is characterized in that: the resistance of described second resistance is 75 ohm.
5. according to each described video discharge circuit in the claim 1 to 4, it is characterized in that: described video driver is an integrated transporting discharging chip, its power supply terminal connection+5V DC power supply.
6. set-top box, comprise decoder and video discharge circuit, it is characterized in that: in described video discharge circuit, comprise a video driver, its input terminal connects decoder, the vision signal of Rcv decoder output, after carrying out the computing processing and amplifying, by the lead-out terminal output of video driver; Between the input terminal of described video driver and ground, be connected with first resistance that is used to adjust video amplitude; On the lead-out terminal of described video driver, be in series with second resistance that is used to carry out impedance matching.
7. set-top box according to claim 6 is characterized in that: the lead-out terminal of described video driver is by the AV terminal of the second resistance junctor top box.
8. set-top box according to claim 6 is characterized in that: described first resistance is variable resistance.
9. set-top box according to claim 6 is characterized in that: the resistance of described second resistance is 75 ohm.
10. according to each described set-top box in the claim 6 to 9, it is characterized in that: described video driver is an integrated transporting discharging chip, and power module is exported+the 5V DC power supply in its power supply terminal junctor top box.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201020599797 CN201821412U (en) | 2010-10-29 | 2010-10-29 | Video operational amplifier circuit and set-top box provided with same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201020599797 CN201821412U (en) | 2010-10-29 | 2010-10-29 | Video operational amplifier circuit and set-top box provided with same |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN201821412U true CN201821412U (en) | 2011-05-04 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 201020599797 Expired - Lifetime CN201821412U (en) | 2010-10-29 | 2010-10-29 | Video operational amplifier circuit and set-top box provided with same |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN201821412U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109406868A (en) * | 2018-12-21 | 2019-03-01 | 云南电网有限责任公司电力科学研究院 | Circuit board, system and program-controlled power signal device applied to simulated failure detection |
| CN109407041A (en) * | 2018-12-21 | 2019-03-01 | 云南电网有限责任公司电力科学研究院 | A kind of simulated failure detection circuit board and simulated failure detection system |
-
2010
- 2010-10-29 CN CN 201020599797 patent/CN201821412U/en not_active Expired - Lifetime
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109406868A (en) * | 2018-12-21 | 2019-03-01 | 云南电网有限责任公司电力科学研究院 | Circuit board, system and program-controlled power signal device applied to simulated failure detection |
| CN109407041A (en) * | 2018-12-21 | 2019-03-01 | 云南电网有限责任公司电力科学研究院 | A kind of simulated failure detection circuit board and simulated failure detection system |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CX01 | Expiry of patent term | ||
| CX01 | Expiry of patent term |
Granted publication date: 20110504 |