KR20130044745A - Tuner and thereby driving - Google Patents

Abstract

Tuner according to an embodiment of the invention the auxiliary circuit to which the signal of the antenna is input; An LNA connected to an output of the auxiliary circuit; An RF amplifier circuit for amplifying and outputting the signal filtered by the LNA; A MOPLL receiving the amplified signal through the RF amplification circuit and tuning to an intermediate frequency signal; And a GPIO for determining whether the signal detected by the MOPLL is a strong field signal or a weak field signal, and controlling an auxiliary circuit according to the strong field signal or the weak field signal.

Description

Tuner and its driving method {TUNER AND THEREBY DRIVING}

The present invention relates to a tuner and a driving method thereof.

Generally, a tuner includes a digital tuner for receiving digital broadcasts, an analog tuner for receiving analog broadcasts, and an analog / digital tuner for receiving both analog and digital broadcasts. The analog / digital tuner, which receives both analog and digital broadcasts, is equipped with a digital saw (SAW) filter that passes only signals in the digital broadcast frequency band and an analog saw (SAW) filter that passes only the analog broadcast frequency band. .

1 is for explaining a conventional tuner. In the conventional tuner, the LNA 100 is added to the input terminal to amplify the gain in order to improve the digital weak field sensitivity specification and the analog weak field reception performance. The weak field performance due to the addition of the LNA (100) is excellent, but on the contrary, there is a side effect (side-effet) in which the strong electric field performance is lowered and the analog interference characteristics are reduced. Therefore, by configuring a switch circuit 140 that can switch the LNA 100 of the tuner on the SET board, a viewer who is an actual user can switch according to the field signal conditions. Switching, 150).

On the other hand, since the actual user performs the LNA switching (Switching, 150), it is not possible to know the exact signal conditions, so it is difficult to switch timing catch (Catching Timing Catch) and also because the signal conditions are different depending on the channel (Ch) , 150) caused inconvenience to itself. This causes a problem that the LNA 100 and the switching circuit added for the reception performance up are lost.

In accordance with an embodiment of the present invention, the present invention relates to a technology for eliminating the trouble of switching a LNA directly by a user and preventing performance deterioration even when a strong electric field is received.

Tuner according to an embodiment of the invention the auxiliary circuit to which the signal of the antenna is input; An LNA connected to an output of the auxiliary circuit; An RF amplifier circuit for amplifying and outputting the signal filtered by the LNA; A MOPLL receiving the amplified signal through the RF amplification circuit and tuning to an intermediate frequency signal; And a GPIO for determining whether the signal detected by the MOPLL is a strong field signal or a weak field signal, and controlling an auxiliary circuit according to the strong field signal or the weak field signal.

According to the embodiment of the present invention, it is possible to eliminate the trouble of the user switching the LNA directly and to prevent the performance deterioration even when receiving the strong electric field.

1 is a view showing a conventional tuner
2 is a diagram illustrating a tuner module according to an embodiment of the present invention.
3 is a circuit diagram of an auxiliary circuit according to an exemplary embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Specific details of other embodiments are included in the detailed description and drawings. BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention, and how to accomplish them, will become apparent by reference to the embodiments described in detail below with reference to the accompanying drawings. Like reference numerals refer to like elements throughout the specification.

2 is a view illustrating a tuner module according to an embodiment of the present invention. 2, the tuner according to the embodiment includes an auxiliary circuit 270, an LNA 200, an IF filter 201, an ANT tuning circuit 202, an RF amplifying circuit 210, and an RF tuning circuit 215. ), MOPLL 220.

The low noise amplifier (LNA) 200 operates with low noise ratio and high amplification, and performs low noise amplification of a high frequency signal received from an antenna. However, since the strong electric field signal is also amplified by the LNA 200, the strong electric field performance of the tuner may be degraded. In order to prevent this, the auxiliary circuit 270 is disposed in front of the LNA 200.

Accordingly, when a strong electric field signal is input, the auxiliary circuit 270 operates through the GPIO pin 225 of the MOPLL 220. Accordingly, performance degradation of the strong field signal may be reduced by reducing the signal input to the LNA 200.

When the level of the signal input to the auxiliary circuit 270 is input, for example, 78 dBuV or more, the auxiliary circuit 270 is turned on through the GPIO pin 225 of the MOPLL 220 to reduce the input signal. By doing so, the signal input to the LNA 200 is input to approximately 68 dBuV. Of course, the criterion for determining whether the input signal is a strong electric field or a weak electric field may be arbitrarily changed. An operation of a specific element of the auxiliary circuit 270 will be described later with reference to FIG. 3.

The IF filter 201 passes a signal of a required frequency band in a circuit having good frequency selectivity. The IF filter 201 may include a series resonant circuit or a parallel resonant circuit.

The ANT tuning circuit 202 includes a circuit for impedance matching between the IF filter 201 and the RF amplifier circuit 210 and is designed to minimize insertion loss.

The RF amplifying circuit 210 includes a circuit for amplifying an RF signal, and changes the amplification degree of the RF signal according to the input auto gain control (AGC) detector 221.

An AGC detector (Auto Gain Control) 221 detects the signal provided by the RF amplifier circuit 210, converts the AGC signal into an AGC signal according to the level of the detected signal, and converts the AGC signal into the RF amplifier circuit 210. Can provide.

The AGC detector 221 may convert the AGC signal according to the signal level and provide the AGC signal to the RF amplifier circuit 210 to adjust the amplification degree. That is, the AGC signal is output near 0 V under the strong electric field signal condition, and the amplification of the RF amplifier circuit 210 is suppressed as much as possible. On the contrary, the AGC signal is output near the 4 V AGC full voltage under the weak electric field signal condition. The amplification of the RF amplification circuit 210 can be maximized.

The RF tuning circuit 215 includes a double tuning circuit and selects a desired RF signal and makes the frequency characteristic flat.

On the other hand, the receiving device including the tuning circuit and the amplifying circuit can receive a broadcast signal transmitted in a frequency of a plurality of bands, for example, can receive a UHF signal, VHF-High signal and VHF-Low signal have.

The MOPLL 220 may receive the amplified signal through the RF amplification circuit 210 and tune to the intermediate frequency signal for output. The MOPLL 220 may convert the signal received from the RF amplifier circuit 210 into an intermediate frequency signal corresponding to a desired broadcast channel and output the converted signal.

The GPIO pin 225 may be connected to the port part. The port part detects whether the signal is a strong field signal or a weak field signal, and connects the auxiliary circuit 270 according to the strong field signal or the weak field signal. I can control it. That is, after detecting whether the signal is a strong field signal or a weak field signal through the ADC signal, the port unit turns on the auxiliary circuit 270 in the case of a strong field signal and turns off in the case of a weak field signal. (Turn off).

The IF signal output from the MOPLL 220 may be connected to a demodulator (not shown). The demodulator may demodulate and output the filtered analog broadcast frequency signal or digital broadcast frequency signal. In this case, the demodulator may demodulate and output the analog / digital broadcast frequency signal into analog / digital audio and analog / digital video signals desired by a program.

3 is a circuit diagram of an auxiliary circuit 270 according to an embodiment of the present invention. The auxiliary circuit has an input connected to an antenna and an output connected to an LNA 200. It may also be connected to the GPIO pin 225 to receive a signal.

The auxiliary circuit 270 may include a first resistor R1, a first diode D1, a second resistor R2, and a first capacitor C1.

The first resistor R1 is to protect the auxiliary circuit 270 and may prevent an infinite current from flowing. The first resistor R1 may be formed to have a value of 2.2 kΩ to 3 kΩ, but is not limited thereto.

An anode of the first diode D1 is connected to the first resistor R1, and a cathode of the first diode D1 is connected to the second resistor R2 and the first capacitor C1.

The second resistor R2 and the first capacitor C1 may be connected in parallel with each other. The second resistor R2 is for reducing the strong electric field signal and may be formed with a value of 15Ω to 27Ω.

The first resistor R1, the diode D1, the second resistor R2, and the first capacitor C1 are connected in series.

The first capacitor C1 may serve to make attenuation rate constant according to frequency, and may be formed to a value of 15pF to 27pF.

Accordingly, in the case of a strong electric field signal, as the auxiliary circuit 270 is turned on, the attenuated signal may pass through the LNA 200, and thus, the digital weak electric field sensitivity standard and the analog weak signal are obtained. Side-effet can improve the field reception performance, and in case of weak field signal, the auxiliary circuit 270 is turned off, resulting in a drop in the strong field performance and inferior analog interference characteristics. ) Can be prevented beforehand.

Features, structures, effects, and the like described in the above embodiments are included in at least one embodiment of the present invention, and are not necessarily limited to only one embodiment. Furthermore, the features, structures, effects, and the like illustrated in the embodiments may be combined or modified with respect to other embodiments by those skilled in the art to which the embodiments belong. Therefore, it should be understood that the present invention is not limited to these combinations and modifications.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be understood that various modifications and applications are possible. For example, each component specifically shown in the embodiments can be modified and implemented. It is to be understood that all changes and modifications that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Claims (9)

An auxiliary circuit to which an antenna signal is input;
An LNA connected to an output of the auxiliary circuit;
An RF amplifier circuit for amplifying and outputting the signal filtered by the LNA; And
A MOPLL receiving the amplified signal through the RF amplification circuit and tuning to an intermediate frequency signal;
And a GPIO for determining whether the signal sensed by the MOPLL is a strong electric field signal or a weak electric field signal, and controlling an auxiliary circuit according to the strong electric field signal or the weak electric field signal. The method of claim 1,
The auxiliary circuit includes a first resistor, a diode, a second resistor and a first capacitor. The method of claim 2,
And the second resistor and the first capacitor are connected in parallel. The method of claim 3,
And the first resistor, the diode, the second resistor, and the first capacitor are connected in series. The method of claim 1,
The GPIO tuner turns on the auxiliary circuit in the case of a strong electric field signal, and turns off the auxiliary circuit in the case of a weak field signal. The method of claim 2,
The first capacitor is a tuner formed of a value of 15pF to 27pF. The method of claim 2,
The first resistor is a tuner formed of a value of 2.2kΩ to 3kΩ. The method of claim 2,
The second resistor is a tuner formed of a value of 15Ω to 27Ω. The method of claim 1,
The MOPLL includes an AGC detector, wherein the AGC detector detects a signal provided from the RF amplifier circuit, converts the signal into an AGC signal according to the level of the detected signal, and provides an AGC signal to the RF amplifier circuit.

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