KR100843399B1

KR100843399B1 - Digital tv network interface module system

Info

Publication number: KR100843399B1
Application number: KR1020070084604A
Authority: KR
Inventors: 이종인
Original assignee: 삼성전기주식회사
Priority date: 2007-08-22
Filing date: 2007-08-22
Publication date: 2008-07-03

Abstract

The present invention relates to a digital TV network interface module system, comprising: an input circuit unit for amplifying an RF signal; The oscillation signal through the first clock connection unit having the P stage and the N stage is changed into a first clock signal and operated according to the first clock signal to convert a frequency signal of a selected channel among the RF signals from the input circuit unit into an intermediate frequency signal. A tuner unit to convert; A COFDM demodulation unit configured to set an oscillation signal through a second clock connection unit having an input terminal and an output terminal as a second clock signal, and operate according to the second clock signal to demodulate an IF signal from the tuner unit in a COFDM scheme; A crystal oscillator connected between the second clock connection units to provide a predetermined oscillation signal; A first filter unit connected between an input terminal of the second clock connection unit, a first connection node of the crystal oscillator, and a P terminal of the first clock connection unit, and configured to block DC; And a second filter unit connected between an output terminal of the second clock connection unit, a second connection node of the crystal oscillator, and an N terminal of the first clock connection unit, and configured to block DC.

Description

Digital TV network interface module system {DIGITAL TV NETWORK INTERFACE MODULE SYSTEM}

The present invention relates to a digital TV network interface module system, and in particular, by using one crystal oscillator, the oscillation signal for the corresponding clock signal can be provided to the COFDM demodulation unit and the tuner unit, thereby enabling further miniaturization. It relates to a digital TV network interface module system.

In general, the digital terrestrial digital broadcasting standard DVB-T (Digital Video Broadcasting-Terrestrial Television) method has a wider application area based on the advantages of reception sensitivity, Single Frequency Network (SFN) characteristics, and mobile reception. have. From fixed products such as general TVs and STBs, such as PMP (Portable Multimedia Player), navigation terminal, portable DVD (Portable) DVD, etc., and continues to expand, such as miniaturization / low power is rapidly made.

In accordance with such miniaturization and low power consumption, the RF part is also manufactured from a conventional VVC diode and a tuner using a MOPLL IC including a modulation function and a phase synchronization loop (PLL) function. Application is increasing rapidly.

1 is a block diagram of a conventional digital TV network interface module system.

The digital TV network interface module system shown in FIG. 1 is a DVB-T NIM (Network Interface Module) system including an RF tuner and a demodulator (DEMOD), which includes an input circuit unit 10 for amplifying and filtering an RF signal, A tuner unit 20 for converting the selected channel frequency signal included in the RF signal from the input circuit unit 10 into an intermediate frequency signal, and a COFDM demodulator for demodulating the IF signal from the tuner unit 20 in a COFDM method; (30).

In this case, the tuner unit 20 is provided with a reference frequency required by using a first crystal oscillator XTAL1 connected to the outside, and the COFDM demodulator 30 uses a second crystal oscillator XTAL2 connected to the outside. Obtain the necessary reference frequency.

However, in the conventional digital TV network interface module system shown in FIG. 1, a crystal oscillator (X-TAL) for supplying an external clock to both the tuner unit (RF tuner IC) and the COFDM demodulator unit (DEMOD IC) is essentially small. Since two crystal oscillators (X-TAL) should be used, one for each area, the oscillation frequency of each crystal oscillator (X-TAL) and its harmonics interfere with the reception band RF signal. Since the use of two crystal oscillators, there is a problem that the material cost of the product is greatly increased, there is a problem that the miniaturization is difficult due to the presence of two crystal oscillators and peripheral circuits.

The present invention has been proposed to solve the above problems of the prior art, the object of which is to provide an oscillation signal for the corresponding clock signal to the COFDM demodulation unit and the tuner unit using one crystal oscillator, Accordingly, the present invention provides a digital TV network interface module system that enables further miniaturization.

In order to achieve the above object of the present invention, the digital TV network interface module system of the present invention, the input circuit unit for amplifying the RF signal; The oscillation signal through the first clock connection unit having the P stage and the N stage is changed into a first clock signal and operated according to the first clock signal to convert a frequency signal of a selected channel among the RF signals from the input circuit unit into an intermediate frequency signal. A tuner unit to convert; A COFDM demodulation unit configured to set an oscillation signal through a second clock connection unit having an input terminal and an output terminal as a second clock signal, and operate according to the second clock signal to demodulate an IF signal from the tuner unit in a COFDM scheme; A crystal oscillator connected between an input terminal and an output terminal of the second clock connection unit to provide a predetermined oscillation signal; A first filter unit connected between an input terminal of the second clock connection unit, a first connection node of the crystal oscillator, and a P terminal of the first clock connection unit, and configured to block DC; And a second filter unit connected between an output terminal of the second clock connection unit, a second connection node of the crystal oscillator, and an N terminal of the first clock connection unit, and configured to block DC.

In addition, the digital TV network interface module system of the present invention is connected between the first connection node and the ground, the first capacitor for finely adjusting the frequency of the oscillation signal of the crystal oscillator; And a second capacitor connected between the second connection node and the ground to finely adjust the frequency of the oscillation signal of the crystal oscillator.

The first filter part may include a capacitor connected between the first connection node and the P terminal of the first clock connection part.

The second filter part may include a capacitor connected between the second connection node and the N terminal of the first clock connection part.

The first clock signal is set to the same frequency as the frequency of the second clock signal.

According to the present invention, by using a single crystal oscillator, it is possible to provide each of the oscillation signal for the clock signal of the COFDM demodulation unit and the tuner unit, thereby making it possible to further reduce the size.

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

The present invention is not limited to the described embodiments, and the embodiments of the present invention are used to assist in understanding the technical spirit of the present invention. In the drawings referred to in the present invention, components having substantially the same configuration and function will use the same reference numerals.

2 is a block diagram of a digital TV network interface module system according to the present invention.

Referring to FIG. 2, the digital TV network interface module system according to the present invention includes an input circuit unit 100 for amplifying an RF signal, a tuner unit 200, a COFDM demodulation unit 300, and a crystal oscillator 400. It includes.

The tuner unit 200 converts an oscillation signal through a first clock connection unit having a P stage (XTAL_P) and an N stage (XTAL_N) into a first clock signal, and operates according to the first clock signal to operate the input. The frequency signal of the selected channel among the RF signals from the circuit unit 100 is converted into an intermediate frequency signal. In this case, the oscillation signal may be changed to the first clock signal by various means, and a simple example may be made by the PLL.

The COFDM demodulation unit 300 sets an oscillation signal through a second clock connection unit having an input terminal X_IN and an output terminal X_OUT as a second clock signal, and operates according to the second clock signal to operate the tuner unit. The IF signal from 200 is demodulated in the COFDM scheme.

The crystal oscillator 400 is connected between an input terminal X_IN and an output terminal X_OUT of the second clock connection unit to provide a predetermined oscillation signal.

In addition, the digital TV network interface module system of the present invention includes a first connection node (N1) between the input terminal (X_IN) of the second clock connection unit and the crystal oscillator 400, and the P terminal ( XTAL_P) connected to each other to block DC between both ends, a second connection node N2 between the output terminal X_OUT of the second clock connection unit and the crystal oscillator 400, and It is connected between the N terminal (XTAL_N) of the first clock connection, and includes a second filter unit 520 for DC blocking.

3 is an embodiment diagram of the digital TV network interface module system of FIG.

Referring to FIG. 3, the digital TV network interface module system of the present invention is connected between the first connection node N1 and the ground to finely adjust the frequency of the oscillation signal of the crystal oscillator 400. The capacitor C10 may be connected between the second connection node N2 and the ground to include a second capacitor C20 for fine-adjusting the frequency of the oscillation signal of the crystal oscillator 400.

In addition, the first filter unit 510 may include a capacitor C51 connected between the first connection node N1 and the P terminal XTAL_P of the first clock connection unit.

The second filter unit 520 may include a capacitor C51 connected between the second connection node N2 and the N terminal XTAL_N of the first clock connection unit.

Therefore, the first clock signal may be set to the same frequency as the frequency of the second clock signal. For example, the frequencies of the first clock signal and the second clock signal may both be set to 20.48 MHz.

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

Referring to FIGS. 2 and 3, the digital TV network interface module system according to the present invention includes an input circuit unit 100, and the input circuit unit 100 includes: The RF signal is amplified and output to the tuner unit 200.

The tuner unit 200 converts an oscillation signal through a first clock connection unit having a P stage (XTAL_P) and an N stage (XTAL_N) into a first clock signal, and operates according to the first clock signal to operate the input. The frequency signal of the selected channel among the RF signals from the circuit unit 100 is converted into an intermediate frequency signal.

In addition, in the digital TV network interface module system of the present invention, the first filter unit 510 is, as described above, the first connection node between the input terminal X_IN of the second clock connection unit and the crystal oscillator 400. (N1) and the P terminal (XTAL_P) of the first clock connection unit. The second filter unit 520 may be disposed between the output terminal X_OUT of the second clock connection unit, the second connection node N2 of the crystal oscillator 400, and the N terminal XTAL_N of the first clock connection unit. Is connected to.

The first filter unit 510 and the second filter unit 520 may block DC interference between the COFDM demodulator 300 and the tuner unit 200, and the first and second filter units ( Since the direct current effects of the COFDM demodulation unit 300 and the tuner unit 200 are blocked by the 510 and 510, the first and second clock signals may be provided using one crystal oscillator.

Meanwhile, referring to FIG. 3, the digital TV network interface module system of the present invention includes a first capacitor C10 connected between the first connection node N1 and a ground, and a second connection node N2 and a ground. It may include a second capacitor (C20) connected between.

The first and second capacitors C10 and C20 may finely adjust the frequency of the oscillation signal of the crystal oscillator 400 according to how the value is set.

In addition, the first filter unit 510 may include a capacitor C51 connected between the first connection node N1 and the P terminal XTAL_P of the first clock connection unit. 520 may include a capacitor C51 connected between the second connection node N2 and the N terminal XTAL_N of the first clock connection unit.

At this time, the first clock signal is set to the same frequency as the frequency of the second clock signal. For example, both frequencies of the first clock signal and the second clock signal may be set to 20.48 MHz.

Explanation of symbols on the main parts of the drawings

100: input circuit portion 200: tuner portion

300: COFDM demodulation unit 400: crystal oscillator

510: first filter unit 520: second filter unit

Claims

An input circuit unit for amplifying an RF signal;

The oscillation signal through the first clock connection unit having the P stage and the N stage is changed into a first clock signal and operated according to the first clock signal to convert a frequency signal of a selected channel among the RF signals from the input circuit unit into an intermediate frequency signal. A tuner unit to convert;

A COFDM demodulation unit configured to set an oscillation signal through a second clock connection unit having an input terminal and an output terminal as a second clock signal, and operate according to the second clock signal to demodulate an IF signal from the tuner unit in a COFDM scheme;

A crystal oscillator connected between an input terminal and an output terminal of the second clock connection unit to provide a predetermined oscillation signal;

A first filter unit connected between an input terminal of the second clock connection unit, a first connection node of the crystal oscillator, and a P terminal of the first clock connection unit, and configured to block DC; And

A second filter unit connected between an output terminal of the second clock connection unit, a second connection node of the crystal oscillator, and an N terminal of the first clock connection unit, and configured to block DC

Digital TV network interface module system comprising a.

The method of claim 1,

A first capacitor connected between the first connection node and ground to fine-tune the frequency of the oscillation signal of the crystal oscillator; And

A second capacitor connected between the second connection node and ground to fine-tune the frequency of the oscillation signal of the crystal oscillator

The digital TV network interface module system further comprises.

The method of claim 2, wherein the first filter unit,

And a capacitor connected between the first connection node and the P terminal of the first clock connection unit.

The method of claim 3, wherein the second filter unit,

And a capacitor connected between the second connection node and the N terminal of the first clock connection unit.

The method of claim 1, wherein the first clock signal,

And a frequency equal to a frequency of the second clock signal.