CN2681493Y - Set-top box video amplifier - Google Patents
Set-top box video amplifier Download PDFInfo
- Publication number
- CN2681493Y CN2681493Y CNU2004200151910U CN200420015191U CN2681493Y CN 2681493 Y CN2681493 Y CN 2681493Y CN U2004200151910 U CNU2004200151910 U CN U2004200151910U CN 200420015191 U CN200420015191 U CN 200420015191U CN 2681493 Y CN2681493 Y CN 2681493Y
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- CN
- China
- Prior art keywords
- resistance
- triode
- circuit
- output circuit
- top box
- Prior art date
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- Expired - Fee Related
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- 239000003990 capacitor Substances 0.000 claims description 8
- 230000000149 penetrating effect Effects 0.000 claims description 8
- 238000001914 filtration Methods 0.000 claims description 6
- 238000010586 diagram Methods 0.000 description 2
- 238000003384 imaging method Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000005764 inhibitory process Effects 0.000 description 1
- 238000004088 simulation Methods 0.000 description 1
Abstract
The utility model relates to a set-top box video amplifier, comprising a power supply filter circuit, an input filter circuit, a grounded base common-collector amplifying circuit, an emitter following circuit and an output circuit. The input filter circuit comprises a capacitance EV1, a resistance RV11 and a resistance RV14. The grounded base common-collector amplifying circuit comprises a triode QV1, a resistance RV10, a resistance RV12, a resistance RV13 and a resistance RV1. The emitter following circuit comprises a triode QV3, a base electrode current-limiting resistance RV4 and an emitting electrode load resistance RV9. The output circuit comprises a capacitance CV9, a capacitance CV10, an electric inductance LV2 and a resistance RV8 completing the impedance matching. The input video signal is connected to the emitting electrode of the triode QV1 through the resistance RV14 of the input filter circuit; the collecting electrode of the triode QV1 is connected to the base electrode resistance RV4 of the triode QV3; the emitting electrode of the triode QV3 is connected to the output circuit. On one hand, the device has low cost; on the other hand, the device has good frequency response characteristic and improved signal driving power.
Description
Technical field
The utility model relates to set-top box, more particularly, relates to a kind of set-top box video amplifying device.
Background technology
Current, Digital Television is fashionable for a time, and set-top box just more and more is subjected to pursuing of market as the last station of Digital Television.Set-top box is digital signal to be transferred to simulation is looked, audio frequency output.
In conventional design, the solution that output often adopts video to amplify IC for the set-top box video, most designers generally select BA7660 (ROHM), this class of TSH22 (ST) IC for use because of considering simplicity of design.But the profit of household electrical appliances is very thin now, and adopts IC can increase cost, and we must consider low cost, the high-performance of design in design for this reason.
It is that the vision signal of sending behind the decoding chip D/A is amplified output that video output drives amplifying circuit, so that better show phase.But in the video drive amplifying circuit, must consider the amplitude-frequency characteristic of an important indicator----video.And the amplitude-frequency characteristic of video is related to the imaging definition of image greatly.Generally the SD digital signal is required imaging 480 lines now, video bandwidth must be accomplished 6M for this reason.For this reason must video the output amplitude-frequency characteristic that drives amplifying circuit necessarily to get well.Promptly amplitude-versus-frequency curve must be smooth in the 0-6MHz scope.SARFT(The State Administration of Radio and Television) requires as follows to amplitude-frequency characteristic: 0MHz-4.8MHz ,+/-0.8dB; 4.8MHz-5.0MHz ,+/-1.0dB; 5.5MHz---6.0MHz ,+0.5/-4.0dB.
The utility model content
The technical problems to be solved in the utility model is, at the above-mentioned defect of high cost of prior art, provides a kind of economical and practical set-top box video output to drive amplifying device.This installs with discrete component and realizes,
The technical scheme that its technical problem that solves the utility model adopts is: construct a kind of set-top box video amplifying device, it is characterized in that, comprise electric source filter circuit, input filter circuit, the cobasis common-collector amplifier, penetrate with circuit, output circuit, described input filter circuit is by electric capacity (EV1), resistance (RV11) and resistance (RV14) constitute, described cobasis common-collector amplifier is by triode (QV1), the resistance (RV10) and the resistance (RV12) of base bias voltage are provided, provide the resistance (RV13) and the collector load resistor (RV1) of emitting stage bias voltage to constitute, described penetrating comprises with circuit and to penetrate with circuit I, described penetrating with circuit I by triode (QV3), base stage current-limiting resistance (RV4), emitter load resistance (RV9) constitutes, described output circuit comprises output circuit I, described output circuit I is by the electric capacity (CV9) of finishing output filtering, electric capacity (CV10) and inductance (LV2) and the resistance (RV8) of finishing impedance matching constitute, incoming video signal is connected to the emitting stage of triode (QV1) by the resistance (RV14) of input filter circuit, the collector electrode of triode (QV1) is connected to the base resistance (RV4) of triode (QV3), and the emitting stage of triode (QV3) connects output circuit.
In set-top box video amplifying device described in the utility model, described penetrating also comprises with circuit and to penetrate with circuit I I, described penetrating with circuit I I by triode (QV2), base stage current-limiting resistance (RV15), emitter load resistance (RV19) level constitutes, described output circuit also comprises output circuit II, described output circuit II is by the electric capacity (CV4) of finishing output filtering, electric capacity (CV2) and inductance (LV11) and the resistance (RV7) of finishing impedance matching constitute, the collector electrode of described triode (QV1) is connected to the base resistance (RV15) of described triode (QV2), and the emitting stage of described triode (QV3) connects output circuit II.
In set-top box video amplifying device described in the utility model, described triode (QV1) adopts 9015.In set-top box video amplifying device described in the utility model, described triode (QV2) and (QV3) employing 9018.
The beneficial effects of the utility model are, adopt the cost of set-top box video amplifying device of the present utility model low, are 1/4 of IC; The driving force of the good frequency response of this device, signal also is improved on the other hand.
Description of drawings
The utility model is described in further detail below in conjunction with drawings and Examples, in the accompanying drawing:
Fig. 1 is the circuit diagram of set-top box video amplifying device of the present utility model.
Embodiment
As shown in Figure 1, be the circuit diagram of set-top box video amplifying device of the present utility model.This circuit employing cobasis-be total to collector comprises electric source filter circuit, input filter circuit, cobasis common-collector amplifier, penetrates with circuit, output circuit.Input filter circuit is made of electric capacity EV1, resistance R V11 and resistance R V14, and the cobasis common-collector amplifier is made of triode QV1, the resistance R V10 that base bias voltage is provided and resistance R V12, the resistance R V13 that the emitting stage bias voltage is provided and collector load resistor RV1.Penetrating with circuit and output circuit to have multichannel, is used to connect the multichannel output equipment.Penetrate in the present embodiment and comprise with circuit and to penetrate with circuit I and penetrating with circuit I I, penetrate with circuit I by triode QV3, base stage current-limiting resistance RV4, emitter load resistance RV9 constitute; Penetrate with circuit I I by triode QV2), base stage current-limiting resistance RV15, emitter load resistance RV19 level constitute.Described output circuit comprises output circuit I and output circuit II, and described output circuit I is made of capacitor C V9, the capacitor C V10 and the inductance L V2 that finish output filtering and the resistance R V8 that finishes impedance matching; Output circuit II is made of capacitor C V4, the capacitor C V2 and the inductance L V11 that finish output filtering and the resistance R V7 that finishes impedance matching.Penetrate with circuit I and be connected with output circuit I; Penetrate with circuit I I and be connected with output circuit II.Incoming video signal is connected to the emitting stage of triode QV1 by the resistance R V14 of input filter circuit, and the collector electrode of triode QV1 is connected to the base resistance RV4 of triode QV3 and the base resistance RV15 of triode QV2.The emitting stage of triode QV3 connects output circuit I; The emitting stage of triode QV2 connects output circuit II.
Cobasis-the triode QV1 of collector adopts 9014,9015 altogether, because 9014,9015 bandwidth is all more than 100M, signal is through coupling capacitance EV1 input triode emitter-base bandgap grading like this, collector electrode output then, because common-base circuit is the Low ESR input, its junction capacitance is less to high frequency effect, and the Frequency Response in the 6M bandwidth will be fine like this.In order to improve carrying load ability, the rear end adds to be penetrated with circuit in addition, and the gating network of rear end is in order to suppress the outer interference of 6M, promptly to play the outer inhibition ability of band.
Claims (4)
1, a kind of set-top box video amplifying device, it is characterized in that, comprise electric source filter circuit, input filter circuit, the cobasis common-collector amplifier, penetrate with circuit, output circuit, described input filter circuit is by electric capacity EV1, resistance R V11 and resistance R V14 constitute, described cobasis common-collector amplifier is by triode QV1, the resistance R V10 and the resistance R V12 of base bias voltage are provided, provide the resistance R V13 and the collector load resistor RV1 of emitting stage bias voltage to constitute, described penetrating with circuit comprises that first penetrates with circuit, described first penetrates with circuit by triode QV3, base stage current-limiting resistance RV4, emitter load resistance RV9 constitutes, described output circuit comprises first output circuit, described first output circuit is by the capacitor C V9 that finishes output filtering, capacitor C V10 and inductance L V2 and the resistance R V8 that finishes impedance matching constitute, incoming video signal is connected to the emitting stage of triode QV1 by the resistance R V14 of input filter circuit, the collector electrode of triode QV1 is connected to the base resistance RV4 of triode QV3, and the emitting stage of triode QV3 connects output circuit.
2, set-top box video amplifying device according to claim 1, it is characterized in that, described penetrating with circuit comprises that also second penetrates with circuit, described second penetrates with circuit by triode QV2, base stage current-limiting resistance RV15, emitter load resistance RV19 level constitutes, described output circuit also comprises second output circuit, described second output circuit is by the capacitor C V4 that finishes output filtering, capacitor C V2 and inductance L V11 and the resistance R V7 that finishes impedance matching constitute, the collector electrode of described triode QV1 is connected to the base resistance RV15 of described triode QV2, and the emitting stage of described triode QV3 connects second output circuit.
According to the described set-top box video of claim 2 amplifying device, it is characterized in that 3, described triode QV1 adopts 9015.
4, set-top box video amplifying device according to claim 3 is characterized in that, described triode QV2 and QV3 adopt 9018.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2004200151910U CN2681493Y (en) | 2004-01-19 | 2004-01-19 | Set-top box video amplifier |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2004200151910U CN2681493Y (en) | 2004-01-19 | 2004-01-19 | Set-top box video amplifier |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN2681493Y true CN2681493Y (en) | 2005-02-23 |
Family
ID=34606354
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNU2004200151910U Expired - Fee Related CN2681493Y (en) | 2004-01-19 | 2004-01-19 | Set-top box video amplifier |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN2681493Y (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102098420A (en) * | 2011-02-24 | 2011-06-15 | 广州视源电子科技有限公司 | Video signal output circuit |
| CN109450392A (en) * | 2018-12-27 | 2019-03-08 | 苏州英诺迅科技股份有限公司 | A kind of distribution emitter following amplifier |
-
2004
- 2004-01-19 CN CNU2004200151910U patent/CN2681493Y/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102098420A (en) * | 2011-02-24 | 2011-06-15 | 广州视源电子科技有限公司 | Video signal output circuit |
| CN109450392A (en) * | 2018-12-27 | 2019-03-08 | 苏州英诺迅科技股份有限公司 | A kind of distribution emitter following amplifier |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20050223 Termination date: 20110119 |