JP2006211702A - Driver circuit having compensation means for transmission line loss - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a driver circuit in which a loss can be compensated for an arbitrary transmission line by adding a rectangular wave or a triangular wave to the original waveform. <P>SOLUTION: The driver circuit includes a signal generator 1, a register 2 for storing pulse-width data and amplitude data of a rectangular wave, rectangular wave generator 3, 4, 5 each for generating a rectangular wave, in accordance with to pulse-width data and amplitude data stored in the register 2, an adder 6 for adding an output 1a of the signal generator 1, the output 3a of the rectangular wave generator 3, an output 4a of the rectangular wave generator 4 and an output 5a of the rectangular wave generator 5, and an amplifier circuit 7 for amplifying the output 6a of the adder 6, and loss of transmission line is compensated for by adding a rectangular wave pulse to a signal waveform. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a system including a driver circuit that transmits a signal using a transmission line, and more particularly to a driver circuit that can compensate for a loss in the transmission line.

Conventionally, loss compensation in a transmission line uses a filter circuit composed of a coil or a capacitor,
The frequency characteristic of the amplifier circuit is adjusted so as to be opposite to the loss characteristic of the transmission line. For example, as disclosed in Japanese Utility Model Laid-Open No. 5-87750, a high frequency component attenuated due to transmission line loss is compensated by increasing the amplification factor at a high frequency using a peaking coil.

Japanese Utility Model Publication No. 5-87750

In a driver circuit having such a conventional loss compensation means, a filter circuit composed of a coil or a capacitor is used. Therefore, when the frequency characteristic of the driver circuit is adjusted according to the loss of one transmission line, the driver circuit is separated. It was difficult to use for this transmission line. In addition, when a coil is used for the filter circuit, there is a problem that it is difficult to integrate the driver circuit.

An object of the present invention is to provide a driver circuit and a transmission line loss compensation method that can be easily applied to an arbitrary transmission line.

Furthermore, an object of the present invention is to provide a driver circuit and a transmission line loss compensation method that are suitable for circuit integration without using a filter circuit including a coil.

In the driver circuit for amplifying a signal to be transmitted and outputting it to a transmission line, the above object is achieved by storing means for storing the pulse width and amplitude of a pulse having a predetermined waveform shape, and the pulses stored in the storing means. One or more pulse generating means for generating a pulse having a width and an amplitude at the rise and fall of the signal to be transmitted, the signal to be transmitted, and the one or more pulse wave generators This can be achieved by a driver circuit having addition means for adding the output pulses and amplification means for amplifying the output of the adder.

As a pulse having a predetermined waveform shape generated by the pulse generation means of the driver circuit, for example, a square wave pulse or a triangular wave pulse is used.

The driver circuit of the present invention has a predetermined pulse width and amplitude in order to compensate for the rising and falling portions of the waveform of the signal to be transmitted, in which high frequency components are attenuated due to loss in the transmission line. One or more pulses having a waveform shape such as a square wave or a triangular wave are added to the signal waveform in synchronization with switching of the signal waveform between a high level (Hi) and a low level (Low).

In the present invention, the storage means is preset according to the loss characteristics of the transmission line used,
The pulse width and amplitude of one or more pulses to be added to the signal waveform are stored. Further, the one or more pulse generating means changes the pulse width and amplitude of the generated pulse according to the pulse width and amplitude stored in the storage means. Therefore, loss compensation can be performed for an arbitrary transmission line by changing data stored in the storage means.

Furthermore, the driver circuit of the present invention is suitable for integration as it does not use a filter circuit having a coil, unlike a conventional driver circuit that performs loss compensation of a transmission line.

ADVANTAGE OF THE INVENTION According to this invention, while being able to compensate the loss in a transmission line in arbitrary transmission lines, the driver circuit suitable for circuit integration and the loss compensation method of a transmission line can be provided.

  Hereinafter, embodiments of the present invention will be described.

Embodiments of a driver circuit having transmission line loss compensation means to which the present invention is applied will be described below with reference to the drawings.

One embodiment of a driver circuit having a transmission line loss compensation means according to the present invention is shown in FIGS.
Will be described with reference to FIG.

For example, as shown in FIG. 1, the driver circuit 8 of the present embodiment includes a signal generator 1 that generates a signal to be transmitted through a transmission line 9, and a square wave pulse used for loss compensation in the transmission line 9. Register 2 for storing the pulse width data and amplitude data, and square wave generators 3, 4, 5... For generating a square wave according to the pulse width data and amplitude data stored in the register 2.

In this embodiment, the output 1a of the signal generator 1, the output 3a of the square wave generator 3, the output 4a of the square wave generator 4, the output 5a of the square wave generator 5, and so on are added. And an amplifier circuit 7 for amplifying the output 6a of the adder 6.

The transmission line loss compensation method performed by the driver circuit 8 of this embodiment is described with reference to FIG.
A description will be given based on the waveform diagram of FIG. In the following, a case where the signal to be transmitted is a digital signal and there are three square wave generators will be described.

A waveform 10 (FIG. 2A) shows a waveform at the time of rising of a part of the signal generated by the signal generator 1. In the case of a driver circuit that does not perform transmission line loss compensation,
A signal having such a waveform 10 is supplied to the transmission line 9 through the amplifier circuit 7 as it is.

Then, due to a loss such as a skin effect in the transmission line 9, the high-frequency component at the rising portion is attenuated, and the waveform becomes dull at the transmission line end 9a as shown by the waveform 11 (FIG. 2B). Such a transmission line loss becomes more prominent as the frequency of the signal to be transmitted becomes higher. For example, in the case of a signal of 100 MHz or higher, the loss due to the skin effect or the like increases even in the transmission line 9 of about 50 cm.

In the present embodiment, for example, in order to compensate for the loss in the transmission line 9 of 50 cm or more in the frequency band of 100 MHz or more, or in the lower frequency band, the transmission line 9 of several meters or more is shown in FIG. Thus, the square wave 12, the square wave 13, and the square wave 14 having the pulse width and the amplitude corresponding to the magnitude and shape of the difference between the waveform 10 and the waveform 11 are to be transmitted (hereinafter referred to as the original waveform). (Referred to as a waveform).

Here, the pulse width and amplitude of each of the square waves 12, 13, and 14 are such that, for example, the difference between the waveform 11 formed by adding these three square waves to the original waveform 10 and the waveform 11 is minimized or previously set. It is determined so that it is below the set threshold value. Further, in consideration of the loss characteristics in the transmission line handled in this embodiment, as shown in FIG. 2C, the pulse width and amplitude of each square wave are
By determining so as to be different from each other, the difference from the waveform 11 can be further reduced.

That is, the waveform of the output 7a of the amplifier circuit 7 is converted into a square wave 12 having different pulse widths and amplitudes, which are obtained in advance as shown by a waveform 15 (thick line portion in FIG. 2D).
The square wave 13 and the square wave 14 are added to the original waveform 10 at the same timing as when the waveform is switched to a high level (Hi) and a low level (Low).

When the waveform 15 formed as described above is supplied to the transmission line 9 and receives a loss in the transmission line 9, a waveform 16 as shown in FIG.

Therefore, according to the present embodiment, the waveform 16 closer to the original waveform 10 can be obtained as compared with the waveform 11 at the transmission line end 9a when the loss compensation in the transmission line is not performed. It becomes possible to compensate for the loss.

The waveform at the rising edge of the signal as shown in FIG. 2 has been described above, but FIG.
As shown in (e) to (e), the same thing can be said when the signal falls. Here, the explanation of the operation of the present embodiment at the time of the fall of the signal is the same as that at the time of the rise and is omitted. In FIG. 3, as in FIG. 2, 10 is the original waveform, 11 is the waveform subjected to the loss in the transmission line 9, 15 is the output waveform of the driver circuit 8 in this embodiment, and 16 is the waveform 1.
Waveforms 5 when receiving a loss by the transmission line 9 are respectively shown.

In the driver circuit 8 of the present embodiment, as described above, it corresponds to the difference between the original waveform 10 and the waveform 11 subjected to the loss in a specific transmission line 9 (FIG. 2C and FIG. 3). (See (c)), the pulse width and amplitude of each square wave are obtained in advance as data and stored in the register 2.

Further, according to the pulse width data and amplitude data stored in the register 2, the square wave generator 3
The square wave generator 4 and the square wave generator 5 cause the square wave 3a, the square wave 4a, and the square wave 5 to be
a is generated, added to the output 5a of the signal generator 5 by the adder 6, and the output 6a of the adder is amplified by the amplifier circuit 7 to obtain the waveform 15.

Here, the square wave generator in the present embodiment makes the pulse width and amplitude of the generated square wave variable. Therefore, when the transmission line 9 is changed, the data stored in the register 2 is changed according to the loss in the transmission line to be newly used, or data corresponding to a plurality of types of transmission lines is stored in the register 2 in advance. The data is stored, and more appropriate data is selected and used at that time.

According to the present embodiment, loss compensation can be performed for an arbitrary transmission line. Furthermore, according to the present embodiment, loss compensation can be realized without using a filter circuit using a coil, so that the driver circuit of the present embodiment can be integrated. Further, by integrating the driver circuit of this embodiment into an integrated circuit, it is possible to easily reduce the size and cost of the driver circuit of this embodiment.

In this embodiment, the number of square wave generators is three, but the number of square wave generators can be any number of one or more. As the number of square wave generators is increased, the compensated waveform 16 of the transmission line end 9a can be made closer to the original waveform 10.

In this embodiment, the square wave generator is configured to be able to generate a square wave corresponding to the pulse width data and amplitude data stored in the register 2, but instead, the square wave generator In this case, only one of the pulse width and the amplitude can be made variable, and the other can be fixed. For example, when the amplitude is fixed, the amplitude value in each square wave generator is the same. According to such a configuration, a storage area for storing fixed data of pulse width data or amplitude data can be omitted from the register 2.

In this embodiment, the amplifier circuit 7 is used. However, when the adder 6 can drive the transmission line 9, the amplifier circuit 7 can be omitted.

Another embodiment of the driver circuit having the transmission line loss compensation means according to the present invention will be described with reference to FIGS. The driver circuit 8 of this embodiment has a configuration for obtaining the pulse width and amplitude of a square wave necessary for loss compensation of the transmission line.

As shown in FIG. 4, the driver circuit 8 of this embodiment has the same configuration as that of the embodiment of FIG. 1, and a signal generator 1 and a register 2 for storing pulse width data and amplitude data of a square wave pulse.
., Square wave generators 3, 4, 5,... For generating a square wave according to the pulse width data and amplitude data stored in the register 2, the output 1a of the signal generator 1, the output 3a of the square wave generator 3, and the square wave. An adder 6 for adding the output 4a of the generator 4 and the output 5a of the square wave generator 5;
And an amplifier circuit 7 for amplifying the output 6a.

In the present embodiment, the same reference numerals are given to the same components as those in the embodiment of FIG. 1 and the description thereof is omitted.

In addition to the above-described configuration, the driver circuit 8 of the present embodiment further includes a digitizing device 17 that digitizes the waveform at the output terminal 7a of the amplifier circuit 7 as a configuration for obtaining the pulse width and amplitude stored in the register 2. And an arithmetic unit 18 for obtaining the pulse width and amplitude of the square wave 12, the square wave 13, the square wave 14... Based on the waveform obtained by the digitizing device 17.

The arithmetic unit 18 detects the output terminal 7 a of the amplifier circuit 7, passes through the transmission line 9, and transmits the transmission line terminal 9.
Based on the digital data of the waveform reflected and returned by a, the waveform 11 at the transmission line end 9a
Further, the output waveform 10 of the amplifier circuit 7 before the transmission line loss compensation is compared with the obtained waveform 11 (see FIGS. 2 and 3), and the difference between the waveforms 10 and 11 is minimized or The pulse width and amplitude of the square wave 12, the square wave 13, the square wave 14,... Are obtained so as to be equal to or less than a predetermined threshold value.

Of the processing operations in the driver circuit 8 of the present embodiment, a compensation value measurement process, which is an example of a processing procedure for obtaining the pulse width and amplitude of each square wave for loss compensation, will be described with reference to the flowchart of FIG. To do. This processing is performed by the transmission line 9 connected to the driver circuit 8 of this embodiment.
The transmission line end 9a is executed in either a short circuit state or an open state.

In this process, first, the transmission line end 9a input by the user or the like is short-circuited,
After accepting the setting of whether it is open (step 501), the transmission line 9 does not perform loss compensation of the transmission line, that is, the signal from the signal generator 1 (see FIG. 2 or FIG. 3) is used as it is.
The driver circuit 8 is operated so as to be supplied to (step 502). More specifically,
The adder 6 is controlled to inhibit the addition of the square wave at this point, or the square wave generator 3
4 and 5 are controlled so as not to generate a square wave.

Next, the output waveform of the amplifier circuit 7 when the transmission line loss is not compensated by the digitizing device 17 (hereinafter referred to as waveform 10), and the waveform 10 passes through the transmission line 9 and is short-circuited or opened. The reflected wave reflected and returned from the transmission line end 9a is digitized (step 503). Here, when the waveform 10 and the reflected wave of the waveform 10 overlap (Yes in Step 504), the processing unit 18 performs a separation process on both waveforms (Step 505).

Next, when it is set that the transmission line end 9a is short-circuited (Y in step 506)
es), since the waveform 10 is inverted upon reflection at the transmission line end 9a,
The reflected wave of 0 is inverted (step 507). Further, the difference between the waveform 10 and the reflected wave of the waveform 10 is calculated by the arithmetic unit 18, and the difference is halved to obtain the difference A between the waveform 10 and the waveform 11 at the transmission line end 9a (step 508). .

Next, the difference between the waveform of the difference A between the waveform 10 and the waveform 11 and the waveform formed by adding the square wave 12, the square wave 13 and the square wave 14 is the minimum or a predetermined threshold value or less. Then, the pulse width and amplitude of each square wave are obtained by the arithmetic unit 18 (step 509), and the obtained pulse width and amplitude of each square wave are written in the register 2 (step 510).

According to this embodiment, it is possible to obtain the pulse width and amplitude of a square wave pulse necessary for loss compensation for an arbitrary transmission line.

In the present embodiment, the waveform 11 when the waveform 10 passes through the transmission line 9 and receives a loss is changed to the waveform 10.
However, the means for obtaining the waveform 11 in the present invention is not limited to this. For example, another digitizing device 17 may be provided at the transmission line end 9a to directly detect and digitize the waveform 11 and transfer the data to the arithmetic device 18. In such a case, there is no need to short-circuit or open the transmission line end 9a.

Another embodiment of the driver circuit having the transmission line loss compensation means according to the present invention will be described with reference to FIGS. The driver circuit of this embodiment uses a triangular wave instead of a square wave in the driver circuit of the embodiment of FIG.

The driver circuit 8 of this embodiment includes a signal generator 1 and a transmission line 9 as shown in FIG.
A register 2 for storing pulse width data and amplitude data of a triangular wave pulse used for loss compensation in the above, a triangular wave generator 19, 20... For generating a triangular wave according to the pulse width data and amplitude data stored in the register 2, and a signal. Output 1a of the generator 1 and output 1 of the triangular wave generator 19
9a and an adder 6 for adding the output 20a of the triangular wave generator 20 and an output 6a of the adder 6
And an amplifier circuit 7 for amplifying the signal.

A transmission line loss compensation method by the driver circuit 8 of this embodiment will be described with reference to the waveform diagram of FIG. In the following description, a case where there are two triangular wave generators will be described. FIGS. 7C and 7D show the results of adding the generated triangular wave pulses.

A waveform 10 (FIG. 7A) is an output of the amplifier circuit 7 when the transmission line loss is not compensated. Waveform 10 is waveform 1 at transmission line end 9a due to loss of skin effect or the like in transmission line 9.
1 (see FIG. 7B). When the triangular wave 21 and the triangular wave 22 having different pulse widths and amplitudes are added to the waveform 11 at the same timing as the switching of the signal waveform to the Hi and Low states as shown in FIG. It can be seen that the waveform 10 is approached.

That is, the output waveform of the amplifier circuit 7 is changed from a waveform 10 to a triangular wave 21 as shown in FIG.
When the waveform 15 is formed by adding the triangular wave 22 and the waveform 15, the waveform 16 similar to the waveform 10 (FIG. 7E) can be obtained even at the transmission line end 9 a. Therefore, transmission line loss can be compensated.

In the driver circuit 8 of this embodiment, as described above, it corresponds to the size and shape of the difference between the original waveform 10 and the waveform 11 subjected to the loss in the transmission line 9 (see FIG. 7C). ) The pulse width and amplitude of each triangular wave are obtained in advance as data and stored in the register 2.

Further, according to the pulse width data and amplitude data stored in the register 2, the triangular wave generator 1
9 and triangular wave generator 20 generate triangular wave 19a and triangular wave 20a, and adder 6
Is added to the output 5a of the signal generator 5, and the output 6a of the adder is amplified by the amplifier circuit 7 to obtain the waveform 16.

Here, the triangular wave generator in this embodiment can change the pulse width and amplitude of the generated triangular wave. For this reason, when changing the transmission line, the data stored in the register 2 is changed according to the loss in the transmission line to be newly used, or data corresponding to a plurality of types of transmission lines is stored in the register 2 in advance. In addition, a configuration is adopted in which more appropriate data is selected and used at that time.

According to this embodiment, loss compensation can be performed on an arbitrary transmission line, and loss compensation can be realized without using a filter circuit using a coil. The circuit can be integrated. Furthermore, the integration of the driver circuit makes it easy to reduce the size and cost of the driver circuit of this embodiment.

Furthermore, since the present embodiment uses a triangular wave pulse, the difference between the waveform 10 and the waveform 11 can be filled more appropriately with a smaller number of pulses compared to the case where a square wave pulse is used. For this reason, this embodiment performs transmission line loss compensation of the same quality with a smaller number of triangular wave generators than the number of square wave generators used in the driver circuit shown in the embodiment of FIG. be able to.

In this embodiment, the number of triangular wave generators is 2, but the number of triangular wave generators can be any number of one or more. As the number of triangular wave generators is increased, the compensated waveform 16 of the transmission line end 9a can be made closer to the waveform 10.

In this embodiment, the triangular wave generator has a configuration in which the pulse width and amplitude of the generated triangular wave are variable. Instead, a configuration in which either the pulse width or the amplitude of the triangular wave generator is fixed. It is good. For example, when the amplitude is fixed, the amplitude value of each triangular wave generator is the same. According to such a configuration, a storage area for storing fixed data of pulse width data or amplitude data can be omitted from the register 2.

In this embodiment, the amplifier circuit 7 is used. However, when the adder 6 can drive the transmission line, the amplifier circuit 7 can be omitted.

Another embodiment of a driver circuit having a transmission line loss compensation means according to the present invention will be described with reference to FIG. The driver circuit 8 of this embodiment has a configuration for obtaining the pulse width and amplitude of a triangular wave necessary for transmission line loss compensation. In the embodiment of FIG. 4, a triangular wave is used instead of a square wave. is there.

As shown in FIG. 8, the driver circuit 8 according to this embodiment includes a signal generator 1, a register 2 that stores pulse width data and amplitude data of a triangular wave pulse, and pulse width data and amplitude data stored in the register 2. The triangular wave generators 19, 20... That generate the triangular wave, the adder 6 that adds the output 1 a of the signal generator 1, the output 19 a of the triangular wave generator 19, the output 20 a of the triangular wave generator 20, and the adder 6 And an amplifier circuit 7 for amplifying the output 6a.

The driver circuit 8 of the present embodiment further includes a digitizing device 17 that digitizes the waveform at the output terminal 7a of the amplifier circuit 7 as a configuration for obtaining the pulse width and amplitude of the triangular wave pulse necessary for the loss compensation of the transmission line. When the waveform 11 at the transmission line end 9a is obtained based on the digitized waveform at the output terminal 7a of the amplifier circuit 7, and the transmission line loss is not compensated, the amplifier circuit 7
The output waveform 10 and the waveform 11 are compared (see FIG. 7), and the pulse widths and amplitudes of the triangular waves 21 and 22 in which the difference between the waveform 10 and the waveform 11 is minimum or less than a predetermined threshold are obtained. And an arithmetic unit 18.

As processing for obtaining the pulse width and amplitude of the triangular wave pulse for loss compensation in the driver circuit 8 of the present embodiment, for example, in the compensation value measurement processing (see FIG. 5) of the embodiment of FIG. A process using a triangular wave pulse instead of a pulse is used. This process
Similar to the compensation value measurement process, the transmission line end 9a is short-circuited or opened.

That is, in this process, first, the driver circuit 8 is operated without performing transmission line loss compensation, and the output waveform 10 of the amplifier circuit 7 when the transmission line loss is not compensated by the digitizing device 17; The reflected wave at the transmission line end 9a of the waveform 10 is detected and digitized. Here, when the waveform 10 and the reflected wave of the waveform 10 overlap, the processing unit 18 performs the separation process. When the transmission line end 9a is short-circuited, the reflected wave of the waveform 10 is inverted by the arithmetic unit 18.

Further, the difference between the waveform 10 and the reflected wave of the waveform 10 is obtained by the arithmetic unit 18, and the difference is 1 /.
2, the difference between the waveform 10 and the waveform 11 at the transmission line end 9a is obtained. The difference between the waveform 10 and the waveform 11 and the waveform formed by adding the triangular wave 21 and the triangular wave 22 are as follows:
Arithmetic apparatus 1 calculates the pulse width and amplitude of each triangular wave that is the minimum or below a predetermined threshold value.
8 and writes the obtained pulse width and amplitude of each triangular wave to the register 2.

According to the present embodiment, it is possible to obtain the pulse width and amplitude of a triangular wave pulse necessary for loss compensation for an arbitrary transmission line.

In this embodiment, the number of triangular wave generators is 2, but the number of triangular wave generators can be any number of one or more.

In this embodiment, the waveform 11 is obtained by the arithmetic unit 18 based on the reflected wave of the waveform 10. However, the waveform 11 is detected directly by providing another digitizing device at the transmission line end 9a. Alternatively, the data may be digitized and the data transferred to the arithmetic unit 18. In this case, it is not necessary to short-circuit or open the transmission line end 9a.

Another embodiment of the driver circuit having the transmission line loss compensation means according to the present invention will be described with reference to FIGS.

In this embodiment, an example of a specific configuration of a square wave generator in a driver circuit using a square wave as in the embodiment of FIG. 1 is shown. In the following description, the transmission line loss at the time of the fall of the signal waveform generated from the signal generator (see FIG. 3) is compensated by using the square wave pulses generated from the two square wave generators. Will be described by way of example.

As shown in FIG. 9, the driver circuit of the present embodiment includes a signal generator 1, a register 2 that stores pulse width data and amplitude data of a square wave pulse, and pulse width data and amplitude data stored in the register 2. Square wave generators 3 and 4 for generating square wave pulses, and a signal generator 1
The adder 6 adds the output 1a of the square wave generator 3, the output 3a of the square wave generator 3, and the output 4a of the square wave generator 4, and an amplifier circuit 7 that amplifies the output 6a of the adder 6.

The adder 6 and the square wave generators 3 and 4 each have a differential amplifier circuit sharing a resistor connected to the collector.

The square wave generator 3 is input to one input of a differential amplifier circuit included in the square wave generator 3.
A variable delay circuit 23 that delays the output 1a of the signal generator 1 according to the pulse width data stored in the register 2, and a variable current that changes the current value of the current flowing through the differential amplifier according to the amplitude data stored in the register 2. Source 25.

Similarly to the square wave generator 3, the square wave generator 4 stores the output 1 a of the signal generator 1 input to one input of the differential amplifier circuit included in the square wave generator 4 in the register 2. The variable delay circuit 24 delays according to the pulse width data, and the variable current source 26 that changes the current value of the current flowing through the differential amplifier according to the amplitude data stored in the register 2.

The operation of the driver circuit of this embodiment will be described with reference to FIG. FIG. 10 shows the time variation of the voltage at the outputs 1a and 1b of the signal generator 1 of this driver circuit, the outputs 23a and 24a of the variable delay circuits of the square wave generators 3 and 4, and the output 6a of the adder 6. It is a waveform diagram showing the time change of the current at the outputs 3a, 4a of the square wave generators 3, 4 as well as showing. In FIG. 10, t1 indicates the start timing of the fall of the signal waveform, and t2 and t3 indicate the pulse widths of the square waves generated by the square wave generators 3 and 4 stored in the register 2, respectively. It is the corresponding timing.

Before time t1, ½ of the current from the current source 25 flows through the output 3a of the square wave generator 3,
Half of the current from the current source 26 flows through the output 4 a of the square wave generator 4. Therefore, the output 6a of the adder 6 is obtained by subtracting the voltage drop due to the sum of 1/2 of the current of the current source 25 flowing through the collector resistor 6b and 1/2 of the current of the current source 26 from the voltage at 6d in the figure. Voltage.

When the output 1a of the signal generator 1 changes from a predetermined low level (Low) to a high level (Hi) corresponding to the falling of the signal waveform at time t1, the output 3a of the square wave generator 3 has The current from the current source 25 flows, and the current from the current source 26 flows through the output 4 a of the square wave generator 4. Therefore, the output 6a of the adder 6 is a voltage obtained by subtracting a voltage drop from the voltage 6d, which is the sum of the current of the current source 6c flowing through the collector resistor 6b, the current of the current source 25, and the current of the current source 26.

In response to the end of the square wave pulse generated by the square wave generator 3 which is one of the two square wave pulses generated for loss compensation at time t2, the output 23a of the delay circuit 23 becomes Low.
Is changed from Hi to Hi, the current 3 of the current source 25 flows through the output 3 a of the square wave generator 3, and the current of the current source 26 flows through the output 4 a of the square wave generator 4. Therefore, the output 6a of the adder 6 is a voltage obtained by subtracting a voltage drop due to the sum of the current of the current source 6c flowing through the collector resistor 6b, 1/2 of the current of the current source 25, and the current of the current source 26 from the voltage 6d. It becomes.

In response to the end of the square wave pulse generated by the square wave generator 4 at time t3, the delay circuit 24
When the output 24a of the square wave generator 3 changes from Low to Hi, the output 3a of the square wave generator 3 is connected to the current source 25.
Of the current source 26 flows, and the current 4 of the current source 26 flows through the output 4 a of the square wave generator 4. Therefore, the output 6a of the adder 6 has a voltage drop from the voltage 6d due to the sum of the current of the current source 6c flowing through the collector resistor 6c, 1/2 of the current of the current source 21 and 1/2 of the current of the current source 21. Reduced voltage.

Therefore, at the output 6a of the adder 6, a square wave pulse having a pulse width and amplitude controlled by the current sources 25 and 26 of the square wave generators 3 and 4 and the variable delay circuits 23 and 24 is used to generate a signal generator. For the falling portion of the signal waveform output from 1, a waveform (see FIG. 3D) in which loss compensation is performed in the transmission line is formed.

According to the present embodiment, the pulse width of the square wave can be changed by the delay amount of the variable delay circuit, and the amplitude of the square wave can be changed by the current amount of the current source. Therefore, by changing the data stored in the register 2 Loss compensation can be performed for any transmission line.

In the present embodiment, the case where loss compensation is performed on the falling portion of the signal waveform generated from the signal generator 1 has been described as an example, but according to the configuration of the present embodiment, exactly as described above, Transmission line loss compensation can also be performed for the rising portion of the signal waveform (see FIG. 2). Although the number of square wave generators is two, the number of square wave generators can be any number of one or more.

In the present embodiment, both the delay circuit and the current source of the square wave generator are variable, but either one may be fixed. For example, when the current source is fixed, the current value of the current source of each square wave generator is made the same. When one of them is fixed as described above, a storage area for storing data corresponding to the fixed one of the pulse width data and the amplitude data is designated as register 2.
Can be omitted.

In the present embodiment, when the collector resistance 6b of the adder 6 is made equal to the characteristic impedance Zo of the transmission line 9, the amplifier circuit 7 can be omitted.

Another embodiment of the driver circuit having the transmission line loss compensation means according to the present invention is shown in FIG.
This will be described with reference to FIG.

In this embodiment, an example of a specific configuration of a triangular wave generator in a driver circuit using a triangular wave is shown. In the following description, an example will be described in which loss compensation at the time of falling of a signal waveform generated from a signal generator is performed using one triangular wave generator.

As shown in FIG. 11, the driver circuit according to the present embodiment includes a signal generator 1, a register 2 that stores pulse width data and amplitude data of a triangular wave, and a triangular wave generator 1 that generates a triangular wave pulse.
9, an adder 6 that adds the output 1 a of the signal generator 1 and the output 19 a of the triangular wave generator 19, and an amplifier circuit 7 that amplifies the output 6 a of the adder 6.

The adder 6 and the triangular wave generator 19 each have a differential amplifier circuit sharing a resistor connected to the collector.

The triangular wave generator 19 has capacitors 19e and 19i connected to the inputs of the differential amplifier circuit included in the triangular wave generator 19 and pulses according to the amplitude data stored in the register 2 at the rise of the output 1a of the signal generator 1. A pulse generator 19b that generates and charges the capacitor 19e at the rising edge, and generates a pulse according to the amplitude data stored in the register 2 when the output 1a of the signal generator 1 falls, and the capacitance at the falling edge 19g pulse generator for charging 19i
And have.

The triangular wave generator 19 further includes a variable current source 19c that gradually sucks the charge of the charged capacitor 19e and a variable current source 19h that gradually sucks the charge of the charged capacitor 19g.

The variable current sources 19c and 19h change the current value according to the pulse width data stored in the register 2. By changing the speed at which the charges accumulated in the capacitors 19e and 19i are sucked by this current value, the variable current sources 19c and 19h The width is adjusted.

The operation of the driver circuit of this embodiment will be described with reference to FIG. 12 shows the outputs 1a and 1b of the signal generator 1 of the driver circuit, the output of the voltage source 19b of the triangular wave generator 19,
FIG. 6 is a waveform diagram showing the time change of the voltage at the output 6a of the adder 6 and the time change of the current at the output 19a of the triangular wave generator 19; In FIG. 12, t1 indicates the start timing of the fall of the signal waveform, and t2 indicates the timing when the triangular wave generated by the triangular wave generator 19 ends.

Prior to time t1, the current 19% of the current value I1 set by the current source 19d flows through the output 19a of the triangular wave generator 19. Therefore, the output 6a of the adder 6 is a voltage obtained by subtracting a voltage drop due to 1/2 of the current value I1 of the current source 19d flowing through the collector resistor 6b from the voltage at 6d in the figure.

When the output 1a of the signal generator 1 changes from Low to Hi at time t1, corresponding to the falling edge of the signal waveform, it is set according to the amplitude data stored in the register 2 generated by the pulse generator 19b. The capacitor 19e is charged by the pulse having the amplitude, and the current having the current value I2 flows through the output 19a of the triangular wave generator 19.

Therefore, the output 6a of the adder 6 is a voltage obtained by reducing the voltage drop due to the sum of the current of the current source 6c and the current of the current value I2 flowing through the collector resistor 6b from the voltage 6d.

Times t1 to t2 correspond to the inclined portion of the triangular wave pulse generated for loss compensation.
That is, the capacitor 19e charged at time t1 by the current source 19c of the triangular wave generator 19
Is gradually sucked out, and the value of the current flowing through the output 19a of the triangular wave generator 19 decreases. Therefore, the voltage at the output 6a of the adder 6 gradually increases.

After time t2, a current half the current value I1 flows through the output 19a of the triangular wave generator 19. Therefore, the output 6a of the adder 6 is a voltage obtained by subtracting a voltage drop from the voltage 6d, which is the sum of the current of the current source 6c flowing through the collector resistor 6b and the current of 1/2 of the current value I1.

Therefore, the output 6a of the adder 6 uses a triangular wave pulse having a pulse width controlled by the variable current source 19c of the triangular wave generator 19 and an amplitude controlled by the pulse generator 19b, from the signal generator 1. A waveform obtained by performing loss compensation in the transmission line is formed on the falling portion of the output signal waveform.

According to the present embodiment, the pulse width of the triangular wave can be varied by the current source 19c, and the amplitude of the triangular wave can be varied by the pulse generator 19b. For this reason, it is possible to perform loss compensation for an arbitrary transmission line simply by changing the data stored in the register 2.

In the present embodiment, the case where loss compensation is performed on the falling portion of the signal waveform generated from the signal generator 1 has been described as an example. However, in the configuration of the present embodiment, in response to the rising edge of the signal waveform. By generating a pulse by the pulse generator 19g simultaneously with the fall of the output 1a of the signal generator 1, loss compensation can be performed on the rising waveform in the same manner as described above. Further, although the number of triangular wave generators is 1, the number of triangular wave generators can be any number of one or more.

In this embodiment, both the pulse width and the amplitude of the triangular wave generator are variable, but one of them may be fixed. For example, when the amplitude is fixed, the amplitude value of each triangular wave generator is the same. As described above, when one is fixed, it is possible to omit from the register 2 a storage area for storing data corresponding to the fixed one of the pulse width data and the amplitude data.

In the present embodiment, when the collector resistance 6b of the adder 6 is made equal to the characteristic impedance Zo of the transmission line 9, the amplifier circuit 7 can be omitted.

An embodiment of a driver IC using a driver circuit having a transmission line loss compensation means according to the present invention will be described with reference to FIG. The driver circuit included in the driver IC of the present embodiment has basically the same configuration as the driver circuit of the embodiment of FIG. The same components as those of the embodiment of FIG. 1 are denoted by the same reference numerals as those of the embodiment of FIG.

As shown in FIG. 13, the driver IC 27 of this embodiment includes a signal generator 1 and a signal generator 1.
One or more terminals 27b for providing information such as timing and pattern to the register, a register 2 for storing pulse width data and amplitude data of a square wave pulse, and a terminal 27c for inputting information on the pulse width and amplitude stored in the register 2 And a serial / parallel converter 26 for converting the serial data input to the terminal 27c into parallel data and supplying pulse width data and amplitude data to each storage area of the register 2.

In this embodiment, the square wave generators 3, 4, 5,... That generate square waves according to the pulse width data and amplitude data stored in the register 2, the output 1a of the signal generator 1, and the square wave generator 3 An adder 6 for adding the output 3a, the output 4a of the square wave generator 4, the output 5a of the square wave generator 5, the amplifier circuit 7 for amplifying the output 6a of the adder 6, and the output of the amplifier circuit 7 And a terminal 27a applied to the transmission line.

According to this embodiment, the driver circuit shown in FIG. 1 without using a filter circuit having a coil can be integrated on one chip. Furthermore, since the driver circuit can be integrated on one chip, the driver circuit or an electronic device provided with the driver circuit can be reduced in size and price.

In this embodiment, the serial / parallel converter 26 is provided between the register 2 and the terminal 27c. However, the number of terminals is increased and the pulse width data and the amplitude data are directly stored in each storage area of the register 2. It is also good.

Further, in this embodiment, the driver circuit configuration of the embodiment of FIG. 1 is used as the driver circuit of the driver IC 27. Instead, the driver circuits of the other embodiments described above (FIGS. 4, 6, and 6) are used. 8, 9 and 11) may be used. The driver circuits shown in FIGS. 4 and 8 have means for determining the pulse width and amplitude of a square wave or a triangular wave. Therefore, when using these circuit configurations, the pulse width and amplitude data are externally input. The terminal 27c for receiving can be omitted.

An embodiment of a semiconductor test apparatus using a driver circuit or driver IC having a transmission line loss compensation means according to the present invention will be described with reference to FIG.

As shown in FIG. 14, the semiconductor test apparatus 37 of the present embodiment includes a timing generator 29, a pattern generator 30, a waveform formatter 31, a digital comparator 32, and a driver circuit 8 having a transmission line loss compensation means. Alternatively, the driver IC 27, the analog comparator 33, and the transmission line 9 for electrically connecting the device under test 34 to the semiconductor test apparatus 37 are provided.

In this embodiment, as the driver circuit 8, any of the driver circuits of the above-described embodiments (see FIGS. 1, 4, 6, 8, 9, and 11) can be used. As the driver IC 27, the driver IC 27 of the embodiment shown in FIG. 13 can be used.

When the driver circuit shown in FIGS. 4 and 8 is used as the driver circuit 8,
As a digitizing device 17 included in the driver circuit 8, an analog comparator 3
3 can be used.

In the present embodiment, the timing signal 29 a created by the timing generator 29 and the test pattern 30 a created by the pattern generator 30 are synthesized by the waveform formatter 31, and the output thereof is converted into a test waveform 8 a by the driver circuit 8. Through the transmission line 9, the device under test 3
4 is given.

The output signal 34a from the device under test 34 as a response to the test waveform 8a is converted into a voltage by the analog comparator 33 and converted into digital values of “0” and “1”. The response signal from the device under test 34 after the digital conversion is sent by the digital comparator 32.
A comparison test is performed at the time indicated by the timing signal 29b with the expected value 30b, which is the response of the non-defective element created by the pattern generator 30, and the quality is determined.

According to this embodiment, since the driver circuit 8 or the driver IC 27 according to the present invention is used, the loss in the transmission line 9 can be compensated when the test waveform 8a is sent to the element under test 34 through the transmission line 9. It becomes possible.

Furthermore, according to the present embodiment, since the loss in the transmission line 9 can be compensated for, if the length of the transmission line 9 to be used is the same as that of the conventional semiconductor test apparatus, a higher-frequency test waveform 8a is generated. This can be applied to the element under test 34, and the timing accuracy of the test waveform 8a can be improved. Further, if the same test frequency and the same timing speed as those of the conventional semiconductor test apparatus are used, the length of the transmission line 9 can be increased, and the degree of freedom in configuration and operation of the semiconductor test apparatus can be increased. The degree of freedom can be improved.

An embodiment of a transmission apparatus that transmits data through a transmission line using a driver circuit or driver IC having a transmission line loss compensation means according to the present invention will be described with reference to FIG.

For example, as shown in FIG. 15, the transmission device 35 of the present embodiment includes a driver circuit 8 or a driver IC 27 having a transmission line loss compensation unit. For example, data having a frequency of 100 MHz or higher is transmitted through a transmission line 9 of 50 cm or higher. A signal is transmitted to the receiving device 36.

In this embodiment, the transmission device 35 and the reception device 36 refer to devices that transmit and receive signals such as data through the transmission line 9, and more specifically, transmission devices, computers, computer peripheral devices, and network devices. Refers to a device composed of measuring instruments and the like.

In this embodiment, the driver circuit 8 (see FIGS. 1, 4, 6, 8, 9, and 11) of any of the above-described embodiments having a transmission line loss compensation means is used as the driver. Circuit 8
Can be used as As the driver IC, the driver IC 27 of the embodiment shown in FIG. 10 can be used.

According to the present embodiment, since it is possible to compensate for the loss of the transmission line 9, transmission is performed as compared with the transmission device 35 including a conventional transmission device, computer, computer peripheral device, network device, measuring instrument, and the like. If the length of the line 9 is the same, a higher frequency signal waveform 8a
Can be transmitted to the receiving device 36. Further, if the transmission frequency is the same, the length of the transmission line 9 can be increased, and the transmission device 35 and the reception device 36 each including a transmission device, a computer, a computer peripheral device, a network device, a measuring instrument, and the like. The degree of freedom of configuration and arrangement can be improved.

In the present embodiment, the data frequency is 100 MHz or more and the length of the transmission line 9 is 50 cm or more, but these conditions are merely examples. Generally speaking, under such conditions, in the conventional device configuration, the loss due to the skin effect in the transmission line begins to become noticeable, but according to the present embodiment, as described in each of the above embodiments, It becomes possible to compensate for the loss in the transmission line.

The circuit diagram which shows the structure of one Example of the driver circuit which has a compensation means of the transmission line loss by this invention. 2A is a waveform diagram showing an output waveform 10 from the driver circuit when transmission line loss compensation is not performed, and FIG. 2B is a waveform diagram showing a waveform 11 after the waveform 10 has passed through the transmission line. 2 (c) is an explanatory diagram showing a square wave corresponding to the difference between the waveform 10 and the waveform 11, and FIG. 2 (d) is a case where loss compensation is performed from the driver circuit according to the embodiment of FIG. FIG. 2E is a waveform diagram showing the waveform 16 after the waveform 15 has passed through the transmission line. 3A is a waveform diagram showing an output waveform 10 from the driver circuit when transmission line loss compensation is not performed, and FIG. 3B is a waveform diagram showing a waveform 11 after the waveform 10 has passed through the transmission line. 3C is an explanatory diagram showing a square wave corresponding to the difference between the waveform 10 and the waveform 11, and FIG. 3D is an output when loss compensation is performed from the driver circuit according to the embodiment of FIG. FIG. 3E is a waveform diagram showing the waveform 16 after the waveform 15 has passed through the transmission line. The circuit diagram which shows the other Example of the driver circuit which has a compensation means of the transmission line loss by this invention. The flowchart which shows an example of the loss compensation value measurement process sequence in the Example of FIG. The circuit diagram which shows the other Example of the driver circuit which has a compensation means of the transmission line loss by this invention. FIG. 7A is a waveform diagram showing an output waveform 10 from the driver circuit when transmission line loss compensation is not performed.

  FIG. 7B: a waveform diagram showing the waveform 11 after the waveform 10 has passed through the transmission line.

  FIG. 7C is an explanatory diagram showing a square wave corresponding to the difference between the waveform 10 and the waveform 11.

FIG. 7D is a waveform diagram showing an output waveform 15 when loss compensation is performed from the driver circuit according to the embodiment of FIG.

FIG. 7E is a waveform diagram showing the waveform 16 after the waveform 15 has passed through the transmission line.
The circuit diagram which shows the other Example of the driver circuit which has a compensation means of the transmission line loss by this invention. The circuit diagram which shows the other Example of the driver circuit which has a compensation means of the transmission line loss by this invention. The wave form diagram for demonstrating the effect | action of the driver circuit of the Example of FIG. The circuit diagram which shows the other Example of the driver circuit which has a compensation means of the transmission line loss by this invention. FIG. 12 is a waveform diagram for explaining the operation of the driver circuit of the embodiment of FIG. The circuit diagram which shows one Example of the driver IC using the driver circuit which has a compensation means of the transmission line loss by this invention. The circuit diagram which shows one Example of the semiconductor test apparatus using the driver circuit or driver IC which has a compensation means of the transmission line loss by this invention. A transmission device comprising a transmission device, a computer and computer peripheral devices, a network device, a measuring instrument, etc., for transmitting data through the transmission line using a driver circuit or driver IC having a transmission line loss compensation means according to the present invention The circuit diagram which shows one Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Signal generator 2 ... Register 3, 4, 5 ... Square wave generator 6 ... Adder 7 ... Amplifier circuit 8 ... Driver circuit 9 ... Transmission line 10 ... Driver's output end when loss compensation is not performed Output waveform 11: Driver output waveform at transmission line end when loss compensation is not performed 12, 13, 14 ... Square wave 15 ... Driver output waveform at driver output end when loss compensation is performed 16 ... Loss compensation The output waveform of the driver at the end of the transmission line when performing 17... Digitizing device 18... Arithmetic device 19, 20 .. Triangular wave generator 21, 22 ... Triangular wave 23, 24 ... Variable delay circuit 25, 26. ... Driver IC
28 ... Serial / Parallel Converter 29 ... Timing Generator 30 ... Pattern Generator 31 ... Waveform Formatter 32 ... Digital Comparator 33 ... Analog Comparator 34 ... Device Under Test 35 ... Transmitting Device 36 ... Receiving Device

Claims (19)

A transmission apparatus characterized in that a signal obtained by adding a square wave or a triangular wave pulse to the rising and falling portions of a signal waveform to be transmitted is output to a transmission line. A driver circuit having a signal generator, a generator that generates a pulse that is a square wave or a triangular wave, and an adder that adds the pulse to the rising and falling portions of the signal waveform generated by the signal generator A transmission device characterized by that. The transmission device according to claim 1 or 2,
The transmitter according to claim 1, wherein the pulse compensates for a loss of a signal generated in the transmission line. A transmission device characterized in that a signal obtained by adding a pulse for compensating for a loss generated in a transmission line to the rising and falling portions of a signal waveform to be transmitted is output to the transmission line. A transmission device that outputs a signal obtained by adding a pulse to the rising and falling portions of a signal waveform to be transmitted to a transmission line,
The difference between the waveform of the signal to be transmitted and the waveform after passing through the transmission line, and the difference in the waveform of the pulse added to the signal waveform to be transmitted are minimum or less than a predetermined threshold value. A transmitting device characterized. 6. The transmission apparatus according to claim 4, wherein the pulse is a square wave or a triangular wave. The transmission apparatus according to claim 1, wherein a plurality of the pulses are provided. 8. The transmission device according to claim 1, wherein the pulse width or amplitude of the pulse changes according to a loss of the transmission line. 9. The transmission apparatus according to claim 7, wherein the plurality of pulses have different shapes. 8. The transmission apparatus according to claim 7, wherein the plurality of pulses have the same width, and the plurality of pulses have different amplitudes. A transmission device for transmitting a signal through a transmission line,
The transmission device stores storage means for storing the width and amplitude of a pulse to be added to the waveform of a signal to be transmitted, and generates a pulse stored in the storage means at the rise and fall of the signal to be transmitted. A transmission apparatus comprising: a driver circuit comprising: a pulse generating means for performing the above-mentioned processing; and an adding means for adding the signal to be transmitted and the pulse output from the pulse wave generator. A transmission device for transmitting a signal through a transmission line,
The transmission device stores storage means for storing at least one of a pulse width and an amplitude of a pulse to be added to a waveform of a signal to be transmitted, and a pulse stored in the storage means when the signal to be transmitted rises. And a transmission circuit comprising: a driver circuit comprising: pulse generation means generated at the falling edge; and addition means for adding the signal to be transmitted and the pulse output from the pulse wave generator. apparatus. A transmission device for transmitting a signal through a transmission line,
The transmission apparatus includes a signal generator that generates a signal to be transmitted through a transmission line, and a square wave set corresponding to a portion of the waveform of the signal to be transmitted that is attenuated due to loss in the transmission line. A register for storing at least one of a pulse width or an amplitude of a pulse; a square wave generator for generating a square wave pulse stored in the register at a rising edge and a falling edge of an output waveform of the signal generator; A driver circuit having an adder for adding the output waveform of the signal generator and the output waveform of the square wave generator, and an amplifier circuit for amplifying the output of the adder and outputting the amplified output to the transmission line. A transmitter characterized by the above. The transmission device according to claim 13, wherein
The driver circuit obtains an output waveform from the amplifier circuit obtained without applying the square wave pulse to the output of the signal generator and a waveform after the output waveform passes through the transmission line. The square wave obtained by the acquisition means and the waveform acquisition means is compared with the waveform before passing through the transmission line and the waveform after passage, and the difference between the two waveforms is minimum or less than a predetermined threshold value. A transmission apparatus, further comprising: an arithmetic circuit for obtaining a pulse width and amplitude of each square wave pulse generated by the generator and storing the obtained pulse width and amplitude in the register. The transmission device according to claim 13 or 14,
The square wave generator includes a differential amplifier circuit that amplifies a difference between two inputs, a delay circuit that delays one input of the differential amplifier circuit according to information on a pulse width stored in the register,
A transmission device comprising: a current source circuit that changes a current value of a driving current of the differential amplifier circuit in accordance with information on an amplitude stored in the register. A transmission device for transmitting a signal through a transmission line,
The transmission device includes a signal generator for generating a signal to be transmitted through a transmission line, and a triangular wave pulse set corresponding to a portion of the waveform of the signal to be transmitted that is attenuated by a loss in the transmission line A register that stores at least one of the pulse width and amplitude of the signal, a triangular wave generator that generates a triangular wave pulse stored in the register at the rise and fall of the output waveform of the signal generator, and the signal generation A driver circuit comprising: an adder that adds the output waveform of the detector and the output waveform of the triangular wave generator; and an amplifier circuit that amplifies the output of the adder and outputs the amplified output to the transmission line. Transmitting device. The transmission device according to claim 16, comprising:
The driver circuit obtains an output waveform from the amplifier circuit obtained without applying the triangular wave pulse to the output of the signal generator and a waveform after the output waveform has passed through the transmission line. And the waveform obtained by the waveform obtaining means, the waveform before passing through the transmission line and the waveform after passing through are compared, and the difference between the two waveforms is minimum or less than a predetermined threshold value. And a calculation circuit for determining the pulse width and amplitude of each triangular wave pulse generated in step (1) and storing the calculated pulse width and amplitude in the register. The transmission device according to claim 16 or 17,
The triangular wave generator includes a differential amplifier circuit that amplifies a difference between two inputs, a capacitor connected to at least one of the inputs of the differential amplifier circuit, and the capacitor according to information related to an amplitude stored in the register. A pulse generation circuit for changing an amplitude of a pulse to be charged; and a current source circuit for changing a current for gradually discharging the charge charged in the capacitor according to information on a pulse width stored in the register. A transmitter characterized by the above. The transmission device according to any one of claims 1 to 18, wherein:
The transmission device is any one of a transmission device, a computer, a computer peripheral device, a network device, and a measuring instrument.

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