TWI501640B - Splitter - Google Patents

Description

Shunt device

The present invention relates to a flow dividing device.

A splitter is a device that splits an input signal (which is a radio frequency (RF) signal) transmitted through a cable into two or more output signals and distributes them to two or more receiving devices. Used in the Community Antenna Television (CATV) system.

Thus, such a shunt device has: an amplifier of a main device that receives an input signal that is not shunted, and amplifies the input signal for output to a device such as a channel tuner; and more than one amplifier It receives the shunted input signal and outputs it for performing additional functions such as picture-in picture (PIP), DVD-R (digital video recorder) or cable modem.

Here, an amplifier that receives an input signal that is not shunted is referred to as a main amplifying unit, and one or more amplifiers to which an input signal is input are referred to as a loop through amplifying unit.

Under such a shunt device, the signal output from the main amplifier is used to watch the television, and the signal output from the monitor amplifier is used to perform additional functions. At this time, the monitor amplifier continues to operate even when the main amplifier is not used.

For this reason, a set-top box having a shunting device maintains a normal operating state even if the television is not in the standby mode (stand-by mode).

As a result, the power consumption of the monitor amplifier is increased.

Therefore, the technical problem to be solved by the present invention is to reduce the power consumed by the shunt device to zero.

According to the present invention, a shunt device includes: a main amplifier receiving an input signal; a monitor amplifier receiving a signal shunted from the input signal; and a shunt circuit having a native transistor; wherein the native transistor has a connection to the input A 汲 terminal between the signal and the drive voltage, a gate terminal connected to the gate voltage, and a source terminal connected to the output terminal of the monitor amplifier.

The driving voltage may have a driving suspension voltage value and a voltage value greater than the driving suspension voltage value. When the driving voltage is the driving suspension voltage value, the primary transistor is turned on, and when the driving voltage is a voltage value greater than the driving suspension voltage value, the native transistor is turned off.

The voltage threshold of the native transistor can be less than 0V.

The gate voltage can be greater than 0V and less than 3.3V.

The voltage between the gate terminal and the source terminal of the native transistor is preferably less than a voltage threshold of the native transistor; the voltage between the gate terminal and the gate terminal of the native transistor is preferably , less than the voltage threshold.

The shunt circuit portion may further include: a first capacitor having one terminal connected to the input signal, the other terminal connected to the 汲 terminal of the native transistor; and a first resistor having one terminal connected to the driving The voltage is connected to the other terminal of the primary transistor.

The shunt circuit portion may further include: a second capacitor having one terminal connected to the source terminal, the other terminal being connected to an output terminal of the monitor amplifier; and a second resistor having one terminal connected to the driving voltage The other terminal is connected to the source terminal of the native transistor.

The main amplifier, the monitor amplifier, and the shunt circuit are formed by an integrated circuit chip.

According to the above feature, when the operation of the monitor amplifier is stopped, since the branch circuit bypass portion provides a path for the input signal to be bypassed, the power consumption of the monitor amplifier is not caused.

Therefore, the power consumption under this shunt device is zero.

10‧‧‧Power Generation Department

20, 20a‧‧ ‧ shunt

21, 22~2n‧‧‧Amplifier

201, 201a‧‧ ‧ branch road

C1, C2‧‧‧ capacitor

R1, R2‧‧‧ resistance

Tr1‧‧‧O crystal

VDD1‧‧‧ input voltage

VDD2‧‧‧ output voltage

Vg‧‧‧ gate voltage

Vin‧‧‧ input signal

Vout1~Voutn‧‧‧ output signal

1 is a block diagram of a shunt device implemented in accordance with an embodiment of the present invention.

Figure 2 shows a block diagram of a shunt device implemented in accordance with another embodiment of the present invention.

The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the invention may be embodied in a variety of different forms and is not limited to the embodiments described herein. Further, in order to clarify the description of the present invention, portions that are not related to the description are omitted in the drawings, and similar reference numerals are used for similar parts throughout the specification.

Next, a flow dividing device realized according to an embodiment of the present invention will be described with reference to the accompanying drawings.

Referring to FIG. 1 , a shunt device implemented according to an embodiment of the invention has a voltage generating unit (10) that receives an input voltage (VDD1) to generate a driving voltage (VDD2) required for operation of the shunt device, and drives the driving voltage (VDD2). The voltage (VDD2) is output; and the shunt (20) is applied with a driving voltage (VDD2) output from the voltage generating portion (10), and the input signal (Vin) received through the input terminal is shunted to output a plurality of Output signal (Vout1 to Voutn).

After receiving the input voltage (VDD1), the voltage generating unit (10) generates a driving voltage (VDD2) required for the operation of the shunt device, and then outputs it.

In the present embodiment, the voltage generating unit (10) changes the magnitude of the driving voltage (VDD2) applied to the shunting device according to the user's operation, and outputs it.

For example, when the user cuts off the power applied to the set-top box having the zero-power shunt device in the embodiment of the present invention by using the power switch, the voltage generating unit (10) outputs a switch for closing. (off) The driving voltage (VDD2) is to suspend the voltage value at which the shunt (20) operates, for example, to output a driving voltage (VDD2) having a driving suspension voltage value of "0V".

However, in the case where power is supplied to the set-top box for the normal operation of the set-top box, the voltage generating portion (10) outputs a switch for driving the voltage (VDD2) to operate the shunt (20). The voltage value, for example, outputs a driving voltage (VDD2) having a driving voltage value of "3.3 V". In this way, the driving voltage (VDD2) at the time of turning on is different from the driving voltage (VDD2) at the time of turning off, and the driving voltage (VDD2) at the time of turning on is larger than the driving voltage (VDD2) at the time of turning off.

In the present embodiment, the magnitude of the driving voltage (VDD2) at the time of turning off and the driving voltage (VDD2) at the time of turning on are two mutually different voltages of 0 V and 3.3 V, but are not limited thereto, and the voltage values may have different changes. .

The shunt (20) has a plurality of amplifiers (21 to 2n) that receive an "input signal" (Vin) input from an input terminal and divide it into a plurality of signals to output an "output signal" via each output terminal. (Vout1 to Voutn); and a shunt turnback portion (201) connected to an output terminal of the amplifier (2n) at the last position for outputting an "output signal" (Voutn) in a plurality of amplifiers (21 to 2n).

Since one input signal (Vin) is shunted into a plurality of signals, the plurality of amplifiers (21 to 2n) have a structure in which they are connected in parallel.

In Fig. 1, an amplifier (21) that directly receives an input signal (Vin) that is not shunted is a main amplifier, and the remaining (n-1) amplifiers (22-2n) to which a shunted input signal (Vin) is applied ) for the monitor amplifier.

In the present embodiment, the number of the monitor amplifiers (22-2n) is plural, but is not limited thereto, and may be one.

In this embodiment, the input signal may be an RF broadcast signal transmitted by the transmitter through wireless communication.

Therefore, the main amplifier (21) may be a channel selector for watching television and processing the received broadcast signal and then outputting, and the plurality of monitor amplifiers (22-2n) may be for implementing PIP (picture-in picture) An amplifier that splits a signal, such as a function, a DVD-R (digital video recorder), or a cable modem.

The branch circuit bypass portion (201) has a first capacitor (C1) whose one terminal is connected to an input terminal to which an input signal (Vin) is applied; and a first resistor (R1) outputted by the voltage generating portion (10) The driving voltage (VDD2) is applied to one terminal of the resistor (R1), and the other terminal of the capacitor (C1) is connected to the other terminal of the resistor (R1); and the transistor (Tr1) is connected to the terminal. On the other terminal of the resistor (R1), a gate voltage (Vg) is applied to the gate terminal, and a source terminal is connected to the output terminal of the amplifier (2n).

The capacitor (C1) is used to block a direct current (DC) component contained in the input signal (Vin) of the shunt circuit portion (201).

The resistor (R1) is used to prevent the impedance balance between the input impedance of the matching amplifier (21~2n) and the input impedance of the shunt bypass (201). The resistor (R1) will have a higher resistance than the input impedance of the amplifier (21~2n), that is, high impedance. In other words, the resistor (R1) has about 10 to 200 times the input impedance of the amplifier (21~2n). The resistance value, for example, the resistance (R1) may range from 10 kΩ to 200 kΩ.

The transistor (Tr1) is a metal oxide silicon transistor and is a native transistor having a voltage threshold (Vth) of less than 0V. In the present embodiment, as an example, the voltage threshold (Vth) may be greater than -200 mV (= -0.2 V) and less than 0 V. Such a native transistor can be fabricated without increasing the number of masks in the basic process of generally manufacturing a transistor, and thus the fabrication of the native transistor does not incur an additional mask cost.

In general, to turn on the transistor (Tr1), the voltage (Vgs) between the gate terminal and the source terminal must be greater than the voltage threshold (Vth).

Conversely, if you want to turn off the transistor (Tr1), the voltage (Vgs) between the gate terminal and the source terminal should be less than the voltage threshold (Vth), and between the gate terminal and the gate terminal. The voltage (Vgd) should also be less than the voltage threshold (Vth).

In general, as long as the voltage (Vgs) between the gate terminal and the source terminal of the transistor satisfies the condition, in actual circuits, the distinction between the 汲 terminal and the source terminal is performed by applying to both terminals. The voltage size is determined. Therefore, in the case of the present embodiment, in addition to the gate terminal, a terminal to which a larger voltage is applied in both terminals of the transistor is used as the 汲 terminal, and a terminal to which a smaller voltage is applied is used as the source terminal.

In the present embodiment, when the driving voltage (VDD2) is in the on state, the bias voltage of the transistor (Tr1) should be the voltage for turning off the transistor (Tr1). Therefore, as mentioned before, the voltage (Vgs) between the gate terminal and the source terminal should be less than the voltage threshold (Vth) (Vgs < Vth), and the voltage (Vgd) between the gate terminal and the gate terminal is also It should be less than the voltage threshold (Vth) (Vgd < Vth).

Wherein, the voltage (Vg) of the transistor (Tr1) gate terminal and the voltage (Vd) of the gate terminal depend on the voltage formed by the driving voltage (VDD2) to satisfy the condition required to turn off the transistor (Tr), That is, the voltage score that satisfies the above two conditions Do not apply to the gate terminal and the 汲 terminal. The source terminal of the transistor (Tr1) is shunted back to the output signal generated by the shunted input signal, so the output voltage of the monitor amplifier (2n) is used to correct the voltage. The bias of the crystal (Tr1).

Therefore, when the driving voltage (VDD2) is turned on, the transistor (Tr1) becomes the off state.

On the other hand, when the driving voltage (VDD2) outputs a voltage at which the driving suspension voltage value is "0V" in the off state, the driving voltage (VDD2) applied to the shunt (20) becomes "0V", thereby a plurality of amplifiers ( 21~2n) becomes non-operating state, and the output signals (Vout1 to Voutn) output by the plurality of amplifiers (21~2n) become "0V", and the gate voltage (Vg) also becomes "0V". Therefore, the voltage (Vgs) between the gate terminal and the source terminal becomes 0V.

In the case of a non-native transistor, a transistor with a typical voltage threshold of 0.4V to 0.8V has a voltage threshold greater than the voltage (Vgs) between the gate terminal and the source terminal. The situation will not be turned on.

However, in the case of the present embodiment, the transistor (Tr1) is a native transistor having a voltage threshold (Vth) of less than 0 V (for example, greater than -0.2 V and less than 0 V), and thus the voltage between the gate terminal and the source terminal ( Vgs) is "0V" which is a value larger than the voltage threshold (Vth), so the transistor (Tr1) is turned on. Thus, even if the applied driving voltage (VDD2) is a driving suspension voltage value for suspending the operation of the shunt (20), the transistor (Tr1) is turned-on.

Thus, when the driving voltage (VDD2) is off, the transistor (Tr1) is turned on.

Thus, in the case of the present embodiment, since the source terminal of the transistor (Tr1) is connected to the output terminal of the amplifier (2n), the transistor (Tr1) is turned on or not depending on the output of the output terminal of the amplifier (2n). The state of the "output signal" (Voutn). As described above, in the case of the present embodiment, the operation of the amplifier (2n) is determined according to the magnitude of the driving voltage (VDD2), so the crystal The turning on or off of the body (Tr1) is determined according to the magnitude of the driving voltage (VDD2), that is, the application or not of the driving voltage value (for example, 3.3 V).

The on or off state of the transistor (Tr1) determines whether the input signal (Vin) passes through the shunt trip portion (201) at the time of output. Therefore, as described above, according to the on or off state of the driving voltage (VDD2), the input signal (Vin) is shunted and then output to the output terminal through the amplifier (2n), or is output to the output via the shunt circuit (201). Output terminal.

The operation of the flow dividing device implemented in accordance with an embodiment of the present invention having the above structure is as follows.

In order to explain the operation flow, it is assumed that the voltage threshold of the transistor (Tr1) is -0.2V, the gate voltage (Vg) is 0V, and the gate voltage (Vd) is 3.3V. Further, according to the operation of the voltage generating unit (10), it is assumed that the driving voltage value of the driving voltage (VDD2) in the on state is 3.3V, and when the driving voltage (VDD2) is in the off state, the driving suspension voltage value is 0V, and accordingly An example of the situation will be explained.

First, when the voltage generating portion (10) applies a driving voltage (VDD2) having a driving voltage value of 3.3 V to the shunt (20), a plurality of amplifiers (21 to 2n) in the shunt (20) operate. The driving voltage (VDD2) is applied, so that the plurality of amplifiers (21 to 2n) become operational.

In this state, as the amplifier (2n) operates, the output signal (Voutn) output from the output terminal of the amplifier (2n) has an appropriately sized voltage and is positive (+).

For example, when the output signal (Voutn) outputs a voltage of 1V, it will make (Vg-Vs) <-1V and (Vg-Vd)=-3.3V, both of which satisfy the less than -0.2V. Voltage threshold is a condition.

Since the voltage (Vgs) between the gate terminal and the source terminal and the voltage (Vgd) between the gate terminal and the gate terminal are both smaller than the voltage threshold (Vth), whereby the transistor (Tr1) is turned off, and the shunt winding portion (201) is thus turned off.

Therefore, the shunt path of the input signal (Vin) is not formed by the shunt circuit (201) but via the monitor amplifier (Voutn).

In this way, the state of the shunt (20) in the normal operation state, that is, the driving voltage (VDD2) is an on state in which the shunt (20) can be operated, and the shunt path of the input signal (Vin) is via Formed by an active amplifier (2n).

However, when the voltage generating unit (20) applies the driving suspension voltage value at which the driving voltage (VDD2) is 0 V to the shunt (20), since the operation of the plurality of amplifiers (21 to 2n) in the shunt (20) is not required, The driving voltage of the size (VDD2), so that the plurality of amplifiers (21-2n) are in an inoperative state.

In this way, since the amplifier (2n) stops operating, the signal (Voutn) output from the amplifier (2n) becomes 0V, and the gate voltage (Vg) is also irrelevant to the set value, and becomes "0". Therefore, the power (P) consumed by the amplifier (2n) is 0 mW (i.e., P = V × I = 0 × I).

Therefore, the voltage (Vgs) between the gate terminal and the source terminal and the voltage (Vgd) between the gate terminal and the gate terminal become 0 V, and thus become a value of a voltage threshold (Vth) greater than -0.2 V. Thereby, even if the driving voltage (VDD2) of the size (for example, 3.3 V) required for the normal operation of the shunt (20) is not applied, the transistor (Tr1) is turned on, and the shunt winding portion (201) is turned on. .

In this way, when the plurality of amplifiers (21 to 2n) are in an inoperative state, since the amplifier (2n) stops operating, the input signal (Vin) does not output the "output signal" via the amplifier (2n), but passes The shunt signal (201) in the open state is maintained and output by the shunt signal.

When the main amplifier (21) and the monitor amplifier (22~2n) are both stopped (ie, in the non-operating state), the monitor amplifier (2n) is turned off. The signal (Voutn) output at the time of closing turns on the transistor (Tr1) of the shunt circuit portion (201), so that the input signal (Vin) is bypassed by the shunt circuit portion (201) alone, instead of passing Monitor amplifier (2n).

Therefore, since it is not necessary to maintain the amplifier (2n) loop-through for providing the shunt path of the input signal (Vin), the power consumed by the monitor amplifier (2n) is "0 mW", so there is no need for the input signal (Vin). The shunt trips, causing the monitor amplifier (2n) to operate independently of itself and consume power.

As described above, the capacitor (C1) is used to cut off the DC component applied to the shunt winding portion (201), and the resistor (R1) is used to achieve high impedance.

The shunting device according to the present embodiment is realized by an integrated circuit chip, so that the cost can be reduced.

Next, referring to Fig. 2, a flow dividing device realized according to another embodiment of the present invention will be described below.

The shunt device shown in Fig. 2 has the same configuration as the shunt device of Fig. 1 except for the shunting portion (201a) of the shunt (20a) as compared with Fig. 1. Therefore, the same components as those in FIG. 1 are denoted by the same reference numerals, and the detailed description thereof will be omitted.

Referring to FIG. 2, the shunt circuit portion (201a) of the shunt (20a) includes a capacitor (C1) connected to the input signal (Vin) and a resistor connected between the driving voltage (VDD2) and the capacitor (C1) ( R1), and a transistor (Tr1) connected between the resistor (R1) and the gate voltage (Vg), and further comprising: a resistor connected between the driving voltage (VDD2) and the source terminal of the transistor (Tr1) (second resistor R2), and a capacitor (second capacitor C2) connected between the source terminal of the transistor (Tr1) and the output terminal of the amplifier (2n).

At this time, the resistor (R2) is the same as the resistor (R1) in Fig. 1 to prevent the input impedance and the shunt circuit of the amplifier (21~2n) that complete the matching. The impedance of the input impedance between (201a) is broken and has the same resistance value as the resistance (R1).

Further, the capacitor (C2) is similar to the capacitor (C1) of Fig. 1 and is a DC component included in the output signal (Voutn) for cutting off the branch-turning portion (201a).

Therefore, in Fig. 1, in order to define the source voltage of the transistor (Tr1), it is necessary to design according to the DC voltage of the amplifier (2n). However, in the case of Fig. 2, the DC voltage of the amplifier (2n) is cut by the capacitor (C2), and the voltage (VDD2) applied to the resistor (R2) is applied in the same manner as the voltage applied to the drain, so that the electric power is made. The on (On) and off (Off) conditions of the crystal (Tr) are not limited to the DC voltage of the amplifier (2n), but are independently controlled, thereby making the design of the shunt winding portion (201a) easier.

The embodiments of the present invention have been described in detail above, but the scope of the present invention is not limited thereto, and the basic concept of the present invention is defined in the appended claims, and various modifications and improvements made by the same in accordance with the present invention are Within the scope of the powers defined by the present invention.

10‧‧‧Power Generation Department

20‧‧‧Splitter

21, 22~2n‧‧‧Amplifier

201‧‧‧Split Circuit

C1‧‧‧ capacitor

R1‧‧‧ resistance

Tr1‧‧‧O crystal

VDD1‧‧‧ input voltage

VDD2‧‧‧ output voltage

Vg‧‧‧ gate voltage

Vin‧‧‧ input signal

Vout1~Voutn‧‧‧ output signal

Claims (8)

A shunt device comprising: a main amplifier receiving an input signal; a monitor amplifier receiving a signal shunted from the input signal; and a shunt circuit having a native transistor; wherein the native transistor has a connection to the input signal and A 汲 terminal between the driving voltages, a gate terminal connected to the gate voltage, and a source terminal connected to an output terminal of the monitor amplifier. The shunt device of claim 1, wherein the driving voltage has a driving suspension voltage value and a voltage value greater than the driving suspension voltage value, wherein the primary transistor is when the driving voltage is the driving suspension voltage value It is turned on, and when the driving voltage is a voltage value greater than the driving suspension voltage value, the native transistor is turned off. The shunt device of claim 1, wherein the voltage threshold Vth of the native transistor is less than 0V. The shunt device of claim 3, wherein the gate voltage is greater than 0V and less than 3.3V. The shunt device of claim 1, wherein a voltage difference between a gate terminal and a source terminal of the native transistor is less than a voltage threshold Vth of the native transistor, and a gate terminal of the native transistor is The voltage difference between the 汲 terminals is also less than the voltage threshold Vth. The shunt device of claim 1, wherein the shunting circuit further comprises: a first capacitor having one terminal connected to the input signal and the other terminal connected to the first terminal of the native transistor; and a first resistor having one terminal connected to the driving voltage and the other terminal connected to the first capacitor The 汲 terminal of a native transistor. The shunt device of claim 1, wherein the shunt circuit further comprises: a second capacitor having one terminal connected to the source terminal and the other terminal connected to an output terminal of the monitor amplifier; The second resistor has one terminal connected to the driving voltage and the other terminal connected to the source terminal of the native transistor. The shunt device of claim 1, wherein the main amplifier, the monitor amplifier, and the shunt circuit are formed by an integrated circuit chip.