KR100631843B1 - Digital dual tuner - Google Patents

Abstract

SUMMARY OF THE INVENTION An object of the present invention is to provide a digital dual tuner in which a dual tuner capable of receiving two broadcasts and simultaneously performing viewing and recording is modularized in one case.

Digital dual tuner of the present invention, the crystal oscillator 100 for generating a reference frequency; A first PLL 210 for controlling first channel tuning according to magnetic control data using the reference frequency of the crystal oscillator 100; A second PLL 220 for controlling second channel tuning according to magnetic control data using the reference frequency of the crystal oscillator 100; A distribution unit 300 for distributing an input high frequency signal RFin; A first digital tuning unit (410) for down-converting the signal distributed by the distribution unit (300) to select a channel according to the first channel tuning control of the first PLL (210); And a second digital tuning unit 420 which down-converts the signal distributed by the distribution unit 300 and selects a channel according to the second channel tuning control of the second PLL 220. Characterized in that produced in one module.

Personal Video Recorder, PVR, Digital Tuner, Watching, Recording

Description

Digital Dual Tuner {DIGITAL DUAL TUNER}

1 is a block diagram of a conventional personal video recorder.

FIG. 2 is a block diagram of the digital tuner of FIG. 1.

3 is a block diagram of another conventional personal video recorder.

4 is a block diagram of a digital tuner having a distribution function of FIG.

5 is a block diagram of a digital dual tuner according to the present invention.

6 is a block diagram of a personal video recorder to which the digital dual tuner of the present invention is applied.

Explanation of symbols on the main parts of the drawings

100: crystal oscillator 210: first PLL

220: second PLL 300: distribution part

410: first digital tuning unit 420: second digital tuning unit

BF1: first buffer BF1: second buffer

BF3: third buffer

The present invention relates to a digital dual tuner applied to a personal video recorder (PVR) set-top box, and the like, and in particular, by implementing a dual tuner in one case that can receive and receive two broadcasts simultaneously, The module of the present invention relates to a digital dual tuner that can not only receive two channels simultaneously, but also simplify the circuit, wiring and connection.

In general, a personal video recorder set-top box (PVR set-top box) that receives DVB-T digital broadcasting, which is a European terrestrial broadcaster, is a set capable of simultaneously watching and recording two broadcasts with a simple reception function. It is changing.

Such a conventional personal video recorder and a digital tuner applied thereto will be described with reference to FIGS. 1 to 4.

1 is a block diagram of a conventional personal video recorder.

FIG. 1 is a front end configuration of a conventional personal video recorder set top box for receiving digital terrestrial broadcasting broadcast in Europe. FIG. The recorder 10 performs OFDM demodulation on a divider 11 connected to an antenna, a first tuner 12 for selecting a channel from a signal distributed by the divider 11, and a signal from the first tuner 12. A first OFDM demodulator 13, a second tuner 14 for selecting a channel from a signal distributed by the divider 11, and a second OFDM demodulated signal from the second tuner 14 Demodulator 15;

This conventional personal video recorder uses a splitter and two tuners to receive two broadcasts in order to simultaneously watch or record.

FIG. 2 is a block diagram of the digital tuner of FIG. 1.

The digital tuner of FIG. 1 shown in FIG. 2 includes a digital tuning unit 21 for down-converting a high frequency signal RFin input from an antenna ANT to select a channel, a crystal oscillator XTAL generating a reference frequency, And a phase locked loop (PLL) for controlling channel selection of the digital tuning unit 21 according to control data using the reference frequency of the crystal oscillator XTAL.

When configuring a personal video recorder using such a conventional digital tuner, as shown in FIG. 1, a splitter and two tuners should be used. In this case, two tuners should be connected to each other by a splitter and a cable. The performance is the same, but there are problems such as price increase due to additional distributor and cable connection, loss generation, and noise inflow of board.

3 is a block diagram of another conventional personal video recorder.

FIG. 3 is a front end configuration of a conventional personal video recorder set top box (PVR SET TOP BOX) for receiving digital terrestrial broadcasting broadcast in Europe. The personal video recorder 30 of FIG. A first tuner 31 for distributing the signal from the inside and the outside, and selecting a channel from the signal distributed therein, and a first OFDM demodulator 32 for OFDM demodulating the signal from the first tuner 31. And a second tuner 33 for selecting a channel from a signal distributed externally by the first tuner 31, and a second OFDM demodulator 34 for OFDM demodulating the signal from the second tuner 33. Include.

Such a conventional personal video recorder includes two different tuners for receiving two broadcasts for viewing or recording.

4 is a block diagram of a digital tuner having a distribution function of FIG.

FIG. 4 is a configuration of the first digital tuner having the distribution function of FIG. 3, which is a distribution unit 41 for distributing the high frequency signal RFin input from the antenna ANT to the inside and the outside, and the distribution unit 41. The digital tuning unit 42 down-converts the high frequency signal RFin distributed internally by the channel selector to select a channel, the crystal oscillator XTAL generating a reference frequency, and the reference frequency of the crystal oscillator XTAL. And a phase locked loop (PLL) for controlling channel selection of the digital tuning unit 21 according to the control data.

In the case of configuring a personal video recorder using the conventional digital tuner, as shown in FIG. 2, the two different tuners are connected to each other by cables using different digital tuners and digital tuners having a distribution function. By doing so, there are problems such as price increase due to cable connection, loss generation and possibility of noise inflow of board.

The present invention has been proposed to solve the above problems, the object of which is to implement a dual tuner that can receive and watch two broadcasts at the same time in a single module, by implementing two modules in one module In addition to receiving channels simultaneously, it also provides a digital dual tuner that simplifies circuitry, wiring, and connectivity.

In order to achieve the above object of the present invention, the digital dual tuner of the present invention

A crystal oscillator for generating a reference frequency;

A first PLL controlling first channel tuning according to magnetic control data using a reference frequency of the crystal oscillator;

A second PLL for controlling second channel tuning according to magnetic control data using a reference frequency of the crystal oscillator;

A distribution unit for distributing an input high frequency signal;

A first digital tuning unit for down-converting a signal distributed by the distribution unit and selecting a channel according to a first channel tuning control of the first PLL; And

And a second digital tuner configured to down-convert the signal distributed by the distributor according to the second channel tuning control of the second PLL to select a channel.

It is characterized by the one module manufactured in one chassis.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In the drawings referred to in the present invention, components having substantially the same configuration and function will use the same reference numerals.

5 is a block diagram of a digital dual tuner according to the present invention.

Referring to FIG. 5, the digital dual tuner according to the present invention controls a first channel tuning according to magnetic control data using a crystal oscillator 100 generating a reference frequency and a reference frequency of the crystal oscillator 100. The first PLL 210 and the second PLL 220 for controlling the second channel tuning according to the magnetic control data using the reference frequency of the crystal oscillator 100 and the input high frequency signal RFin are distributed. A first digital tuning unit 410 for down-converting the signal distributed by the distribution unit 300 and selecting a channel according to the first channel tuning control of the first PLL 210; And a second digital tuning unit 420 which down-converts the signal distributed by the distribution unit 300 and selects a channel according to the second channel tuning control of the second PLL 220.

In addition, the digital dual tuner of the present invention, including the above-described configuration, can be manufactured in one chassis to solve the conventional problems such as separate wiring connection or noise.

In addition, the digital dual tuner may include a first buffer BF1 connected between the crystal oscillator 100 and the second PLL 220, and a first connection connected between the distribution unit 300 and the first digital tuning unit 410. The second buffer BF2 may further include a third buffer BF3 connected between the distribution unit 300 and the second digital tuning unit 420.

The distribution unit 300 includes a high pass filter 310 for passing an input high frequency signal over a predetermined frequency, a shear amplifier 320 for amplifying the signal from the high pass filter 310 with a set gain, and And a distribution circuit 330 for distributing the signal from the front end amplifier 320 to the first digital tuning unit 410 and the second digital tuning unit 420, respectively.

The first digital tuning unit 410 is a first tracking filter 411 for passing the input signal to the variable band according to the channel selection, and RF for amplifying the signal from the first tracking filter 411 with a set gain The amplifier 412, the second tracking filter 413 for passing the signal from the RF amplifier 412 to the variable band according to the channel selection, and the signal from the second tracking filter 413 to the first A down converter 414 for down-converting and outputting an IF signal according to the first channel tuning control of the PLL 210, an IF filter 415 for passing an IF from the down converter 414, and the IF filter ( IF amplifier 416, which amplifies the IF signal from 415 to a set gain.

The second digital tuning unit 420 is a first tracking filter 421 for passing the input signal to the variable band according to the channel selection, and RF for amplifying the signal from the first tracking filter 421 with a set gain The amplifier 422, a second tracking filter 423 for passing the signal from the RF amplifier 422 to a variable band according to channel selection, and a signal from the second tracking filter 423 to the first PLL. A down converter 424 down-converting according to the first channel tuning control of 210 to output an IF signal, an IF filter 425 for passing IF from the down converter 424, and the IF filter 425 IF amplifier 426 amplifies the IF signal from the set gain.

6 is a block diagram of a personal video recorder to which the digital dual tuner of the present invention is applied.

Referring to FIG. 6, when a personal video recorder is configured using the digital dual tuner of the present invention as shown in FIG. 5, the digital dual tuner of the present invention has a function of separately tuning two channels. Two OFDM demodulators are connected to this digital dual tuner.

Hereinafter, the operation and effects of the present invention will be described in detail with reference to the accompanying drawings.

The present invention is a splitter, the two tuners are made of separate modules (module), in the case of manufacturing a personal video recorder using each module, in order to solve the problems caused by the wiring connection between each module and the noise problem accordingly, The distribution function and the dual tuning function are included in one chassis to manufacture a module, which solves the conventional wiring connection problem and noise problem, which will be described with reference to FIGS. 5 and 6.

Referring to FIG. 5, the digital dual tuner according to the present invention uses one crystal oscillator 100, and the crystal oscillator 100 includes a first PLL 210 and a second PLL 220 generating a reference frequency. Will output

In this case, since one crystal oscillator 100 is used, cost can be reduced and configuration can be simplified, while the first PLL 210 and the second PLL 220 are provided via the crystal oscillator 100. ) May be connected to each other to interfere with each other. To exclude this, a first buffer BF1 may be connected between the crystal oscillator 100 and the second PLL 220, and thus, at the second PLL 220 side. The signal separation between the crystal oscillator 100 and the first PLL 210 is blocked, thereby improving the signal separation between the first PLL 210 and the second PLL 220.

In addition, in order to reduce the number of pins connected to the digital tuner of the present invention, a data input terminal for control data is commonly connected and utilized, and an address terminal for controlling the PLL IC of each tuning unit is not provided separately, and digital tuning is performed. By setting the address pin (AS pin) of each PLL IC to supply a different voltage inside the negative, different addresses are used.

In addition, the first PLL 210 controls the first channel tuning according to the magnetic control data using the reference frequency of the crystal oscillator 100, and the second PLL 220 controls the crystal oscillator 100. The second channel tuning is controlled according to the magnetic control data using the reference frequency.

Meanwhile, the high frequency signal RFin input through the antenna ANT is distributed to the first digital tuning unit 410 and the second digital tuning unit 420 by the distribution unit 300. The high pass filter 310 of the distribution unit 300 passes the input high frequency signal more than a predetermined frequency, the shear amplifier 320 amplifies the signal from the high pass filter 310 with a set gain, The distribution circuit 330 distributes the signal from the front end amplifier 320 to the first digital tuning unit 410 and the second digital tuning unit 420, respectively.

Here, in order to exclude interference between the first digital tuning unit 410 and the second digital tuning unit 420 connected to the distribution unit 300, between the distribution unit 300 and the first digital tuning unit 410. The second buffer BF2 is connected to the second buffer BF2, and the third buffer BF3 is connected between the distribution unit 300 and the second digital tuning unit 420 to connect with the first digital tuning unit 410. The signal separation between the second digital tuning units 420 is improved.

That is, when two tuning units are operated simultaneously, a buffer is provided at the output side of the distribution unit to attenuate mutual interference caused by the two oscillation frequencies to attenuate the level of the oscillation frequency at the input of the tuning unit.

In this case, the first digital tuning unit 410 selects a channel by down converting the signal distributed by the distribution unit 300 according to the first channel tuning control of the first PLL 210. In addition, the second digital tuning unit 420 down-converts the signal distributed by the distribution unit 300 and selects a channel according to the second channel tuning control of the second PLL 220.

The first digital tuning unit 410 will be described in detail. After the signal distributed and input by the distribution unit 300 is passed through the variable band according to channel selection by the first tracking filter 411, the RF is transmitted. The amplifier 412 amplifies the set gain.

Thereafter, the amplified signal is passed through the variable band according to channel selection by the second tracking filter 413 and then output to the down converter 414. In this case, the down converter 414 receives the second tracking filter ( The signal from 413 is down-converted according to the first channel tuning control of the first PLL 210 to output an IF signal.

The IF signal is passed by the IF filter 415 and then amplified by the gain in the IF amplifier 416 to be output.

The second digital tuning unit 420 will be described in detail. After the signal distributed and input by the distribution unit 300 is passed through the variable band according to channel selection by the first tracking filter 421, the RF is transmitted. Amplified by the set gain in the amplifier 422.

Thereafter, the amplified signal is passed through the variable band according to channel selection by the second tracking filter 423 and then output to the down converter 424. At this time, the down converter 424 is the second tracking filter ( The signal from 423 is down-converted according to the second channel tuning control of the second PLL 220 to output an IF signal.

The IF signal is passed by the IF filter 425 and then amplified by the set gain in the IF amplifier 426 and output.

6 is a block diagram of a personal video recorder to which the digital dual tuner of the present invention is applied.

Referring to FIG. 6, when a personal video recorder is configured using the digital dual tuner of the present invention as shown in FIG. 5, the digital dual tuner of the present invention has a function of separately tuning two channels. Two OFDM demodulators are connected to this digital dual tuner.

According to the present invention as described above, the distribution unit and the two single-conversion tuning unit must be configured integrally in one chassis, so that the two broadcasts can be simultaneously received, and additionally, the signal distribution when two tuners are applied In this case, it is possible to improve the possibility of price increase, loss generation, and noise inflow of the board due to the additional distributor and cable connection generated by connecting two tuners with the distributor and cable.
More specifically, in a conventional digital tuner, the input of the splitter is coupled to the antenna (Ant) and typically a din jack, and the output of the splitter is connected at both ends to connect with the first digital tuner or the second digital tuner. A coaxial cable of 10 cm or more in the form of a phone jack shall be used.
Accordingly, when the coaxial cable is coupled, insertion loss and matching loss due to length and jack contact resistance, characteristic impedance, and the like, but the dual tuner of the present invention are the same. Since there is no need to use a cable built into the chassis (a single metal body), of course, insertion loss can be solved, and matching circuits can be designed to eliminate matching losses. Can be.
In addition, as in the related art, the divider, the first digital tuner, and the second digital tuner each have a separate structure, and the ground is formed differently in RF, so that the sampling frequency and the reference clock of the board due to the potential difference are different. Although digital noise, such as the like, may be introduced into the first and second digital tuners, as in the present invention, the first digital tuner and the second digital tuner are configured in the same chassis so that a metal shield is provided. Since there is no cable-like structure, and based on an external board, the same ground is formed in one chassis, so the influence of the board noise can be eliminated.

In addition, by configuring the distribution unit and the two tuning units as a single module, it is possible to reduce the number of pins connected to the tuner from the outside to facilitate a user application.

In addition, the reference crystal oscillator may be configured to use a buffer to drive two PLLs with one crystal oscillator.

In addition, by configuring a buffer at the output of the divider, it is possible to reduce the possibility of mutual interference by the two oscillation frequencies when two tuners are simultaneously operated at the input.

Claims (6)

A crystal oscillator 100 for generating a reference frequency; A first PLL 210 for controlling first channel tuning according to magnetic control data using the reference frequency of the crystal oscillator 100; A second PLL 220 for controlling second channel tuning according to magnetic control data using the reference frequency of the crystal oscillator 100; A first buffer BF1 connected between the crystal oscillator 100 and the second PLL 220; A distribution unit 300 for distributing an input high frequency signal RFin; A first digital tuning unit (410) for down-converting the signal distributed by the distribution unit (300) to select a channel according to the first channel tuning control of the first PLL (210); And Including a second digital tuning unit 420 to down-convert the signal distributed by the distribution unit 300 in accordance with the second channel tuning control of the second PLL 220 to select a channel, Digital dual tuner, characterized in that made in one chassis in one module. delete The digital dual tuner of claim 2, wherein A second buffer BF2 connected between the distribution unit 300 and the first digital tuning unit 410; And A third buffer BF3 connected between the distribution unit 300 and the second digital tuning unit 420. Digital dual tuner further comprising a. The method of claim 1, wherein the distribution unit 300 A high pass filter 310 for passing an input high frequency signal over a preset frequency; A shear amplifier 320 for amplifying the signal from the high pass filter 310 with a set gain; Distribution circuit 330 for distributing the signal from the front end amplifier 320 to the first digital tuning unit 410 and the second digital tuning unit 420, respectively. Digital dual tuner comprising a. The method of claim 1, wherein the first digital tuning unit 410 A first tracking filter 411 for passing an input signal to a variable band according to channel selection; An RF amplifier 412 for amplifying the signal from the first tracking filter 411 with a set gain; A second tracking filter (413) for passing the signal from the RF amplifier (412) to a variable band according to channel selection; A down converter 414 for down-converting the signal from the second tracking filter 413 according to the first channel tuning control of the first PLL 210 to output an IF signal; An IF filter 415 for passing IF from the down converter 414; And An IF amplifier 416 which amplifies the IF signal from the IF filter 415 to a set gain Digital dual tuner comprising a. The method of claim 1, wherein the second digital tuning unit 420 A first tracking filter 421 for passing an input signal to a variable band according to channel selection; An RF amplifier 422 for amplifying the signal from the first tracking filter 421 to a set gain; A second tracking filter 423 for passing the signal from the RF amplifier 422 into a variable band according to channel selection; A down converter 424 for down converting the signal from the second tracking filter 423 according to a first channel tuning control of the first PLL 210 to output an IF signal; An IF filter 425 for passing the IF from the down converter 424; And IF amplifier 426 for amplifying the IF signal from the IF filter 425 to a set gain Digital dual tuner comprising a.

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