CN203243463U - Ground receiving system of digital television broadcast signal and set top box - Google Patents
Ground receiving system of digital television broadcast signal and set top box Download PDFInfo
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- CN203243463U CN203243463U CN 201320247679 CN201320247679U CN203243463U CN 203243463 U CN203243463 U CN 203243463U CN 201320247679 CN201320247679 CN 201320247679 CN 201320247679 U CN201320247679 U CN 201320247679U CN 203243463 U CN203243463 U CN 203243463U
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- tuner
- power supply
- chip
- digital television
- television broadcast
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Abstract
The utility model discloses a ground receiving system of a digital television broadcast signal and a set top box. The circuit board of the system is provided with a power supply circuit, a tuner, a demodulation chip and a main decoding chip. The tuner is a silicon tuner or a CAN tuner that is completely compatible with the silicon tuner in terms of packaging structure. The tuner receives a ground digital television broadcast signal, converts the signal into a differential intermediate-frequency signal, and then transmits the signal into the demodulation chip for demodulation to generate a TS data flow. The main decoding chip receives the TS data flow outputted by the demodulation chip for decoding to generate a composite video signal and an audio signal, and outputs the signals through an audio-video output port. The system utilizes the small-size packaged silicon tuner or a CAN tuner completely compatible with the silicon tuner in terms of packaging structure in the design of the system circuit of the set top box, so that hardware cost is reduced, the overall product performance is improved, and a design scheme can be flexibly selected with a development cycle greatly reduced.
Description
Technical field
The utility model belongs to the digital TV receiving system technical field, specifically, relates to the set-top box that a kind of circuit system for receiving and process the ground digital television broadcast signal designs and adopts described circuit system design.
Background technology
Ground digital television broadcast is part important in the radio and television system.Ground digital television broadcast has overcome not only that the artificial antenna TV is subject to disturb, poor image quality, the shortcoming of ghost image is arranged, and can also transmit the nearly TV programme of 8 covers in a television channel, has greatly improved the utilance of wireless frequency spectrum.The larger variation that terrestrial DTV brings is, can stably receive high-quality TV programme signal under mobile status, thereby so that in-car TV, portable hand-held TV become possibility.
Since two thousand six, after the issue of the national standard of Digital Television Terrestrial Broadcasting, the tuner that is applicable to the GB terrestrial broadcast standard occurs successively.Because the standard in early stage and the uncertainty in market, the type of the tuner of each manufacturer production is multifarious, and the size of applicable frequency range, tuner encapsulation, the position of tuner pin and definition mode etc. also are varied.This just causes set-top box and all-in-one manufacturer in the early development stage of product, need to carry out for various types of tuners the Design of Compatibility of circuit system, not only workload is large, and the R﹠D cycle is long, and is subject to the layout of system circuit board and the structure of product.
Along with the development of digit chip technology, the area of demodulation chip that is applicable to the GB terrestrial receiving system is more and more less, and required peripheral circuit is more and more simpler, has saved to a great extent thus the area of system circuit board.But, because tuner pack continues former design always, therefore so that the bottleneck that is designed to the restriction product form of tuner pack.And, the tuner that different manufacturers is produced, because the design in early stage is inconsistent, in case more conversion tuner or demodulation chip just need again fabric swatch, more again piece installing, the very trouble that operates has been wasted a lot of debug times, causes the R﹠D cycle to prolong.
Summary of the invention
The purpose of this utility model is to provide a kind of ground digital television broadcast receiving system, carry out the global design of circuit system by the tuner that adopts small-sized package, thereby when saving board area, so that the selection of the global design scheme of system and product case is more flexible.
In order to solve the problems of the technologies described above, the utility model is achieved by the following technical solutions:
A kind of ground digital television broadcast receiving system is provided with power circuit, tuner, demodulation chip and main decoder chip at the circuit board of system, and described tuner is the fully compatible CAN tuner of silicon tuner or encapsulating structure and silicon tuner; Described tuner transfers to demodulation chip and generates the TS data flow with demodulation after receiving the ground digital television broadcast signal and converting differential intermediate frequency to; The TS data flow of described main decoder chip receiving demodulation chip output, and decoding generation composite video signal and audio signal are exported by audio and video output interface.
Because when selecting dissimilar tuner to be welded on the circuit board, different tuners needs different working powers.In order to satisfy the different power reguirements of different tuners, improve the compatibility of board design, be provided be used to the assemble welding district of welding described tuner at described circuit board, each pass pin for tuner in described assemble welding district is laid with it one to one pad, the pad that wherein is used for the power pins of welding tuner connects the first DC power supply by the first gating device respectively, connects the second DC power supply by the second gating device; Described the first DC power supply and the second DC power supply are respectively described silicon tuner and the required different operating power supply of CAN tuner.
Preferably, described the first gating device and the second gating device preferably adopt zero resistance or jumper wire device, realize that different tuners are communicated with from the selection of different DC power supply.
Further, be provided with the first voltage stabilizing chip in described power circuit, the input of described the first voltage stabilizing chip connects the first DC power supply, converts the first DC power supply to second DC power supply by the output output of the first voltage stabilizing chip.
Further again, in described power circuit, also be provided with the second voltage stabilizing chip, the input of described the second voltage stabilizing chip connects the second DC power supply, converts the second DC power supply to the 3rd DC power supply by the output output of the second voltage stabilizing chip; Described the second DC power supply and the corresponding different power pin that connect demodulation chip of the 3rd DC power supply.
Actual power for demodulation chip and dissimilar tuner needs, and it is 5V that described the first DC power supply is set, and the second DC power supply is 3.3V, and the 3rd DC power supply is 1.2V.
Preferably, the differential intermediate frequency by the output of described tuner preferably via the matched filtering circuit transmission to described demodulation chip.
Further, the I of described demodulation chip
2The C bus pin is connected the I of tuner with filter circuit by pull-up circuit
2The C bus pin, transmission of control signals.
For control that tuner is gained, the intermediate-frequency gain control pin of described demodulation chip is connected the gain control making pin of tuner with filter circuit by pull-up circuit, the transmission gain control signal.
Based on above-mentioned ground digital television broadcast receiving system, the utility model has also proposed a kind of set-top box that adopts described ground digital television broadcast receiving system design, system circuit board in set-top box is provided with power circuit, tuner, demodulation chip and main decoder chip, and described tuner is silicon tuner or encapsulating structure and the complete compatible CAN tuner of silicon tuner; Described tuner transfers to demodulation chip and generates the TS data flow with demodulation after receiving the ground digital television broadcast signal and converting differential intermediate frequency to; The TS data flow of described main decoder chip receiving demodulation chip output, and decoding generation composite video signal and audio signal are exported by audio and video output interface.
Compared with prior art, advantage of the present utility model and good effect are: ground digital television broadcast receiving system of the present utility model adopts the silicon tuner of small-sized package and encapsulation is complete and the CAN tuner design system circuit of silicon tuner compatibility, can save taking up room of system circuit board thus, simplify the structural design of system circuit board, shorten the R﹠D cycle.It is applied in the circuit system design of set-top box the overall volume that not only can dwindle the set-top box product, the Miniaturization Design of realization product; And by the internal circuit board of set-top box being carried out the Design of Compatibility of tuner, can realize that thus a circuit board is to the compatibility assembling of dissimilar tuner, so that the selection of scheme is more flexible, not only improved the versatility of board design, reduced the complete machine cost of product, and promoted the overall performance of product, improved the industrial competition of product.
Description of drawings
In order to be illustrated more clearly in the technical scheme among the utility model embodiment, the below will do to introduce simply to the accompanying drawing of required use in embodiment or the description of the Prior Art.Apparently, the accompanying drawing in the following describes only is embodiment more of the present utility model, for those of ordinary skills, under the prerequisite of not paying creative work, can also obtain according to these accompanying drawings other accompanying drawing.
Fig. 1 is the theory diagram of a kind of embodiment of the ground digital television broadcast receiving system that proposes of the utility model;
Fig. 2 is the circuit theory diagrams of a kind of embodiment of tuner and part peripheral circuit thereof among Fig. 1;
Fig. 3 is the partial circuit schematic diagram of power circuit among Fig. 1;
Fig. 4 is another part circuit theory diagrams of power circuit among Fig. 1;
Fig. 5 is the circuit theory diagrams of a kind of embodiment of demodulation chip and peripheral circuit thereof among Fig. 1;
Fig. 6 is the circuit theory diagrams of a kind of embodiment of matched filtering circuit;
Fig. 7 is the circuit theory diagrams of a kind of embodiment of gain control signal transmission circuit;
Fig. 8 is the circuit theory diagrams of a kind of embodiment of bus signal transmission circuit.
Embodiment
Below in conjunction with the accompanying drawing among the utility model embodiment, the technical scheme among the utility model embodiment is clearly and completely described.Obviously, described embodiment only is a part of embodiment in the utility model, rather than whole embodiment.Based on the embodiment in the utility model, those of ordinary skills are not making all other embodiment that obtain under the creative work prerequisite, all belong to the scope of the utility model protection.
For the advantage that makes technical solutions of the utility model is clearer, below in conjunction with drawings and Examples the utility model is explained.
Embodiment one, and referring to shown in Figure 1, the ground digital television broadcast receiving system of the present embodiment mainly partly is comprised of power circuit, tuner, demodulation chip, main decoder chip and audio and video output interface etc.Wherein, power circuit and can satisfy the different needs for electricity of dissimilar tuner for each provides required different operating power supply with electric loading in the system.In order to reduce the volume of system circuit board, to make things convenient for the Miniaturization Design of product, tuner pack preferably adopts the silicon tuner of small-sized package or the CAN tuner fully compatible with the encapsulation of silicon tuner (the can tuner with radome that namely adopts discrete component to form) to carry out the specific design of circuit system.Connect wired television signal line by described silicon tuner or CAN tuner, receive the ground digital television broadcast signal that TV station the sends form transmission of radiofrequency signal (usually with), and convert differential intermediate frequency to and export demodulation chip to.After described demodulation chip is separated the mediation analog-to-digital conversion process to the differential intermediate frequency that receives, generating digital signal (being preferably formed the TS data flow), transfer to the decoding processing that the main decoder chip carries out digital signal, and then decoding generation composite video signal CVBS and audio signal Audio, export via audio and video output interface (the Video terminal that for example arranges on the set-top box).The composite video signal CVBS and the audio signal Audio that process output by the ground digital television broadcast receiving system can directly transfer to outside television set, to realize the user selection of TV programme are play.
For the versatility that improves system circuit board and the flexibility of design, the present embodiment carries out Design of Compatibility for dissimilar silicon tuner and CAN tuner on circuit board, to realize that the same circuit board is to the design requirement of the compatible assembling of dissimilar tuner.
In order to realize above-mentioned purpose of design, when the present embodiment is designed for the assemble welding district of welding tuner at circuit board, the peripheral circuit of tuner is carried out Design of Compatibility, to realize the support to dissimilar tuner.Referring to shown in Figure 2, because the selected tuner of the present embodiment or be the silicon tuner, be encapsulating structure fully and the CAN tuner of silicon tuner compatibility, therefore, when the assemble welding district of design tuner, can according to pin number and the installation position of such tuner, one to one pad be set with it targetedly, to make things convenient for the assemble welding of tuner in the assemble welding district.Consider that the required working power of dissimilar tuner is different, for example CAN tuner and part silicon tuner need the power supply of 5V, and some silicon tuner then needs the power supply of 3.3V.In order to realize the Design of Compatibility of circuit board, in described pad, preferably will connect the first DC power supply, for example the DC power supply 5V_BBO of 5V by the first gating device (for example zero resistance R177) respectively for the pad of the power pins MB that welds tuner T5; Connect the second DC power supply by the second gating device (for example zero resistance R181), the DC power supply 3.3V_DTMB_TUNER of 3.3V for example, and then according to the concrete need for electricity of selecting the tuner T5 of assembling on the circuit board, select wherein one road gating device connection, T5 provides stable dc power supply for such tuner.When adopting zero resistance as gating device, the mode that can adopt welding or not weld zero resistance R177/R181 realizes that the power pins MB of tuner is communicated with the selection of the first DC power supply 5V_BBO or the second DC power supply 3.3V_DTMB_TUNER.
Certainly, other components and parts that described the first gating device and the second gating device also can select jumper wire device etc. to have gate action carry out the specific design of circuit system, and the present embodiment does not specifically limit this.
The different DC power supply required for dissimilar tuner can provide by the output of the power circuit on the circuit board, referring to shown in Figure 3.The multipath voltage regulation chip can be set in described power circuit realize the conversion output of multi-channel dc power supply.Wherein, U11 is the first voltage stabilizing chip, and its input VIN is connected the first DC power supply, describe as an example of 5V DC power supply 5V_BBO example, and by filter capacitor C49 ground connection.Utilize the first voltage stabilizing chip U11 to convert 5V DC power supply 5V_BBO to second DC power supply, the DC power supply 3.3V_DTMB_TUNER of 3.3V for example, carry out exporting after filtering is processed by the output VOUT of the first voltage stabilizing chip U11 and via filter capacitor C50, C51, and then for dissimilar tuner provides its required 5V DC power supply or 3.3V_DTMB_TUNER, to satisfy the power demands of dissimilar tuner.
In described power circuit, also be provided with the second voltage stabilizing chip U602, referring to shown in Figure 4, be used for conversion and generate the 3rd DC power supply, to satisfy the different needs for electricity of other loads.Generating the required 1.2V DC power supply of demodulation chip U2 take conversion describes as example, the input VIN of the second voltage stabilizing chip U602 is passed through filter capacitor C609, E2 connects the second DC power supply, the 3.3V DC power supply 3.3V_DTMB_TUNER that namely exports by the first voltage stabilizing chip U11 conversion, carry out after DC converting processes via the second voltage stabilizing chip U602, generate the DC power supply 1.2VDD of 1.2V, by the output VOUT of the second voltage stabilizing chip U602 and via inductance L 35 and capacitor C 52, C131, after the filter circuit that EC14 forms is processed, export the 1.2V power pin of demodulation chip U2 to, PLLVDD12 for example, VDD12, ADCVDD12 etc. are in conjunction with shown in Figure 5.For the required 3.3V DC power supply of demodulation chip U2, can provide by the DC power supply 3.3V_DTMB_TUNER of the first voltage stabilizing chip U11 output, transfer to the 3.3V power pin of the first voltage stabilizing chip U11, VDD33 for example is to satisfy the different power demands of demodulation chip U2.
Certainly, for other required power supplies of other loads, can adopt and design the more mode of multipath voltage regulation chip in power circuit, change generating the required different power supplies of different loads, the present embodiment is not limited in above giving an example.
In order to improve the stability of signal transmission between tuner T5 and the demodulation chip U2, the present embodiment will be by the differential intermediate frequency IF_OUT1 of tuner T5 output, IF_OUT2 is via resistance R 169, R511 and capacitor C 128, C129, C507, C53, after the matched filtering circuit that C55 forms carries out impedance matching and filtering processing, generate differential signal I_N, I_P exports ADCIN and the ADCIP pin of demodulation chip U2 to, referring to shown in Figure 6, to realize the solution mediation analog-to-digital conversion process to differential intermediate frequency, and then generation TS data flow, TS interface TD_DATA0 ~ TD_DATA7 via demodulation chip U2, TS_CLK, TS_SYNC, TS_VALID exports the main decoder chip to, finishing the decoding of digital signal processes, and then generation meets, and television set receives and composite video signal CVBS and the audio signal Audio of broadcast request, transfer to television set via audio and video output interface, to realize displaying the play of TV programme, in conjunction with shown in Figure 5.
The gain control signal required for tuner T5 work can provide by the intermediate-frequency gain control pin IF_AGC output of demodulation chip U2, in conjunction with Fig. 2, Fig. 5, shown in Figure 7, the gain control making pin IFAGC that connects tuner T5 via resistance R 15 pull-up circuit that is connected with 3.3V DC power supply 3.3V_DTMB_TUNER and the filter circuit that is formed by capacitor C 502, resistance R 35, R78 and build-out resistor R502, R123, the transmission gain control signal.
For the required system clock of demodulation chip U2 work, then can be generated by the crystal oscillating circuit external with it provides.Referring to shown in Figure 5, described crystal oscillating circuit can be comprised of crystal oscillator chip X401, resistance R 402 and capacitor C 401 ~ C403.
In order to transmit control command, demodulation chip U2 is by its I
2The pull-up circuit that C bus pin SCL, SDA are connected via resistance R 124, R166 and 3.3V DC power supply 3.3V_DTMB_TUNER and the I that is connected tuner T5 by the filter circuit that capacitor C 33, C122 form
2The C bus pin, the transmission of the control commands such as realization channel selection is in conjunction with Fig. 2, Fig. 5, shown in Figure 8.
Certainly; above-mentioned explanation is not to be to restriction of the present utility model; the utility model also is not limited in above-mentioned giving an example, and the variation that those skilled in the art make in essential scope of the present utility model, remodeling, interpolation or replacement also should belong to protection range of the present utility model.
Claims (10)
1. ground digital television broadcast receiving system, it is characterized in that: the circuit board in system is provided with power circuit, tuner, demodulation chip and main decoder chip, and described tuner is silicon tuner or encapsulating structure and the complete compatible CAN tuner of silicon tuner; Described tuner transfers to demodulation chip and generates the TS data flow with demodulation after receiving the ground digital television broadcast signal and converting differential intermediate frequency to; The TS data flow of described main decoder chip receiving demodulation chip output, and decoding generation composite video signal and audio signal are exported by audio and video output interface.
2. ground digital television broadcast receiving system according to claim 1, it is characterized in that: be provided be used to the assemble welding district of welding described tuner at described circuit board, each pass pin for tuner in described assemble welding district is laid with it one to one pad, the pad that wherein is used for the power pins of welding tuner connects the first DC power supply by the first gating device respectively, connects the second DC power supply by the second gating device; Described the first DC power supply and the second DC power supply are respectively described silicon tuner and the required different operating power supply of CAN tuner.
3. ground digital television broadcast receiving system according to claim 2, it is characterized in that: described the first gating device and the second gating device are zero resistance or jumper wire device.
4. ground digital television broadcast receiving system according to claim 2, it is characterized in that: in described power circuit, be provided with the first voltage stabilizing chip, the input of described the first voltage stabilizing chip connects the first DC power supply, converts the first DC power supply to second DC power supply by the output output of the first voltage stabilizing chip.
5. ground digital television broadcast receiving system according to claim 4, it is characterized in that: in described power circuit, also be provided with the second voltage stabilizing chip, the input of described the second voltage stabilizing chip connects the second DC power supply, converts the second DC power supply to the 3rd DC power supply by the output output of the second voltage stabilizing chip; Described the second DC power supply and the corresponding different power pin that connect demodulation chip of the 3rd DC power supply.
6. ground digital television broadcast receiving system according to claim 5, it is characterized in that: described the first DC power supply is 5V, and the second DC power supply is 3.3V, and the 3rd DC power supply is 1.2V.
7. each described ground digital television broadcast receiving system in 6 according to claim 1 is characterized in that: the differential intermediate frequency by described tuner output via the matched filtering circuit transmission to described demodulation chip.
8. each described ground digital television broadcast receiving system in 6 according to claim 1 is characterized in that: the I of described demodulation chip
2The C bus pin is connected the I of tuner with filter circuit by pull-up circuit
2The C bus pin.
9. each described ground digital television broadcast receiving system in 6 according to claim 1, it is characterized in that: the intermediate-frequency gain control pin of described demodulation chip is connected the gain control making pin of tuner with filter circuit by pull-up circuit.
10. a set-top box is characterized in that: be provided with in described set-top box such as the described ground digital television broadcast receiving system of each claim in the claim 1 to 9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201320247679 CN203243463U (en) | 2013-05-09 | 2013-05-09 | Ground receiving system of digital television broadcast signal and set top box |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201320247679 CN203243463U (en) | 2013-05-09 | 2013-05-09 | Ground receiving system of digital television broadcast signal and set top box |
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| CN203243463U true CN203243463U (en) | 2013-10-16 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN 201320247679 Expired - Fee Related CN203243463U (en) | 2013-05-09 | 2013-05-09 | Ground receiving system of digital television broadcast signal and set top box |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105915306A (en) * | 2016-06-14 | 2016-08-31 | 北京海尔集成电路设计有限公司 | China digital radio CDR receiving terminal and realization method of the receiving terminal |
| CN107734357A (en) * | 2017-03-08 | 2018-02-23 | 南京邦众电子商务有限公司 | Method and system based on broadcasting and TV movement, DTV wirelessly transmitting data |
-
2013
- 2013-05-09 CN CN 201320247679 patent/CN203243463U/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105915306A (en) * | 2016-06-14 | 2016-08-31 | 北京海尔集成电路设计有限公司 | China digital radio CDR receiving terminal and realization method of the receiving terminal |
| CN107734357A (en) * | 2017-03-08 | 2018-02-23 | 南京邦众电子商务有限公司 | Method and system based on broadcasting and TV movement, DTV wirelessly transmitting data |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20131016 Termination date: 20190509 |