JP5360066B2 - Transmitting apparatus, receiving apparatus, transmitting / receiving apparatus, and transmitting / receiving method - Google Patents

Description

(Description of related applications)
The present invention is based on the priority claim of Japanese Patent Application No. 2008-241172 (filed on Sep. 19, 2008), the entire contents of which are incorporated herein by reference. Shall.
The present invention relates to a transmission device, a reception device, a transmission / reception device, and a transmission / reception method, and more particularly to an analog signal transmission device, a reception device, a transmission / reception device, and a transmission / reception method.

  There is an increasing demand for non-contact communication technology that realizes non-contact data communication between LSIs that are in contact with each other or separated by a distance of about several hundred μm. In particular, in a system in package (SiP) in which a plurality of LSI chips are stacked to function as one system, as a transmission method that eliminates the need for inter-chip wiring, or for inspecting LSI on a wafer As a technique for improving the life of a probe card and the number of simultaneous measurements using the probe card by eliminating the need for an inspection needle (needle) used in the probe card, demand for a non-contact communication technique is increasing.

  Short-distance non-contact communication technology includes a communication system based on electromagnetic induction between coils (inductors) formed in a chip, a flat plate for each chip, and parallel plate capacitors ( A communication method based on capacitive coupling in which (capacity) is formed is included. However, in the latter method, the communication distance is limited to several μm to several tens of μm, and transmission between a plurality of chips is difficult. Therefore, the former method is mainly adopted.

  FIG. 9 is a block diagram showing a configuration of a conventional transmission / reception apparatus. Referring to FIG. 9, the transmission / reception device includes a transmission device 111 and a reception device 112. The transmission device 111 includes a data transmission circuit 201 and a transmission coil 206. The receiving device 112 includes a data receiving circuit 202 and a receiving coil 207.

  The data transmission circuit 201 outputs a pulse-like current I that changes with time to the transmission coil 206 as shown in FIG. At this time, an induced magnetic field proportional to the time derivative dI / dt of the current I is generated, and the induced electromotive force shown in FIG.

  For example, when transmitting the signal “0”, as shown in FIG. 10, first, the current flowing through the transmission coil 206 is increased to generate a positive voltage (induced electromotive force) at the reception coil 207. Next, the current flowing through the transmission coil 206 is reduced to generate a negative voltage at the reception coil 207. On the other hand, when transmitting the signal “1”, first, the current flowing through the transmission coil 206 is decreased to generate a negative voltage at the reception coil 207. Next, the current flowing through the transmission coil 206 is increased to generate a positive voltage at the reception coil 207. The data receiving circuit 202 amplifies the voltage of the receiving coil 207, detects the difference between these two pulse voltages, and converts it into digital data.

  In non-contact communication, although digital data can be transmitted, there is a problem that it is difficult for the receiving device 112 to output a DC voltage of an arbitrary level (magnitude). In order to generate an arbitrary DC voltage having a constant magnitude in the reception device 112, the current in the transmission coil 206 of the transmission device 111 must be monotonously increased (or decreased) at a constant rate. That is, it is necessary to generate a constant dI / dt. However, in order to increase (or decrease) the current flowing through the transmission coil 206 at a constant rate over a long period of time, it is necessary to flow a strong current through the transmission coil 206, and there is a certain limit in the current driving capability. The transmitting device 111 cannot generate such a strong current.

  Therefore, in the non-contact communication method, the following method can be considered to output an analog signal. That is, the value of the analog signal to be output is transmitted as digital data from the transmission device 111 to the reception device 112, and after receiving the digital data, the reception device 112 has a digital-analog conversion circuit (not shown) provided therein. This is a method of outputting an analog signal using Patent Document 1 describes a delta modulation method in which an output voltage is increased or decreased by a certain amount in accordance with “0” and “1” of an input digital signal for each clock cycle.

  On the other hand, as a method for generating a DC signal without using a digital-analog conversion circuit, for example, as described in Patent Document 2, a received pulse signal is passed through a low-pass filter (low-pass filter) circuit. Thus, a method in which the DC component of the pulse signal is used as the DC signal of the output signal is also conceivable.

  As another method, a method may be considered in which a voltage integration circuit (not shown) is provided in the reception device 112 and the voltage integration circuit integrates the output voltage value by a minute amount V each time a voltage pulse is input to the reception device 112. . At this time, a DC voltage of a desired level is obtained in the receiving device 112 by transmitting the pulse N times. As an example of such a method, Patent Document 3 describes a method in which an induced electromotive force of a receiving coil is half-wave rectified or full-wave rectified and then passed through an integrating circuit. According to this method, a DC voltage proportional to the number of pulses N can be output.

JP-A-8-316915 JP 2004-208112 A JP 2004-320083 A

The entire disclosures of Patent Documents 1 to 3 are incorporated herein by reference.
The following analysis was made by the present inventors. A general digital-analog conversion circuit that converts a digital (binary) signal into an analog signal and the delta modulation method described in Patent Document 1 have a large conversion circuit area and require a dedicated clock for the digital-analog conversion circuit. There is a problem that the output voltage range is narrow (that is, a digital-analog conversion circuit corresponding to the entire range from the ground level to the power supply voltage level is difficult). Furthermore, there is a problem that the area and power consumption of the amplifier circuit for converting a minute induced electromotive force input to the receiving device 112 into an input signal (that is, a digital signal) of the digital-analog conversion circuit is large.

のように、受信装置１１２における誘導起電力の時間積分はつねに０となる。このとき、誘導起電力をローパスフィルタに入力して得られるフィルタ出力電圧も０となってしまう。したがって、特許文献２に記載されているようなローパスフィルタを用いる方法においては、任意の出力レベルの直流電圧を生成することはできないという問題がある。By the way, in the non-contact communication, the time of the induced electromotive force V in the receiving device 112 regardless of the shape of the pulse between two time points (time 0 and T in FIG. 11) where no current flows by the data transmission circuit 201 The integration is zero. That is, the following formula

As described above, the time integral of the induced electromotive force in the receiving device 112 is always zero. At this time, the filter output voltage obtained by inputting the induced electromotive force to the low-pass filter also becomes zero. Therefore, in the method using the low-pass filter as described in Patent Document 2, there is a problem that a DC voltage of an arbitrary output level cannot be generated.

  Further, according to the method described in Patent Document 3, when changing the DC voltage value, for example, when it is desired to change the voltage to a voltage lower than the previous DC voltage value, the DC voltage is once returned to 0 (reset). ), It is necessary to input the pulse again. Therefore, there is a problem that a separate reset signal is required, and a transmitter and a receiver for transmitting and receiving the reset signal are separately required. Further, there is a problem that the value of the minute amount V fluctuates due to transmission intensity, variation of the amplifier circuit of the receiving device, and the like, and it is difficult to set a highly accurate voltage value.

  As described above, in the conventional short-distance non-contact communication using a coil (inductor) or a capacitor, there is a problem that it is difficult to output a DC voltage of an arbitrary level by the receiving circuit. In addition, according to the method of providing a digital-analog converter in the receiving device, the area of the conversion circuit is large, the output range is narrow, a dedicated clock or reset signal is required, and a minute induction signal input to the receiving device is required. There is a problem that the area and power consumption increase due to the amplifier circuit for converting power into a digital signal. Furthermore, there is a problem that it is difficult to set a highly accurate voltage value due to variations in transmission intensity, amplification circuits in the receiving device, and the like.

  Therefore, in a transmission / reception device that outputs a DC voltage via non-contact communication, it is a problem to reduce the area and power consumption of the reception device. Another problem is to provide means for compensating for the value of the output DC voltage when there is variation in the intensity of the transmission current and the reception circuit.

The receiving apparatus according to the first aspect of the present invention is:
A receiving coil whose electromotive force is induced by the transmitting coil;
When a first current whose rise time is shorter than the fall time is induced to flow through the transmission coil, a second current in a direction opposite to the first current is generated when the rise time is longer than the fall time. A filter circuit having different transmission characteristics for the electromotive force when induced by flowing through the transmission coil; and
An integration circuit for integrating the current output by the filter circuit.
That is, the receiving apparatus causes the first coil to have a rise time shorter than the fall time or a second current that is longer than the fall time and opposite to the first current. A receiving coil in which an electromotive force is induced;
A filter circuit for filtering an electromotive force induced in the receiving coil;
An integration circuit for integrating the current output by the filter circuit.

A transmitting apparatus according to the second aspect of the present invention is:
A transmission coil for inducing an electromotive force in the reception coil by electromagnetic induction;
A first current having a rise time shorter than the fall time, and a data transmission circuit for outputting a second current in a direction opposite to the first current to the transmission coil, the rise time being longer than the fall time. I have.

A filter circuit according to a third aspect of the present invention is:

A first diode and a second diode having a predetermined logic threshold, the cathode of the first diode being connected to the anode and the first node of the second diode; A bidirectional diode having an anode connected to the cathode of the second diode and an output node;
A unity gain buffer in which the input voltage and the output voltage are equal, and one of the inputs is connected to the output node and the output is connected to the second node;
And a resistor connected to the first node and the second node.

The transmission / reception method according to the fourth aspect of the present invention is:
Outputting a first current having a rise time shorter than the fall time and a second current having a reverse sign to the first current and having a rise time longer than the fall time to the transmission coil;
A step of inducing an electromotive force in the receiving coil based on the current output to the transmitting coil;
Inputting the electromotive force into a filter circuit having different transmission characteristics with respect to the electromotive force when induced by the first current and when induced by the second current;
Integrating the current output by the filter circuit.
That is, the transmission / reception method is
Flowing a first current having a rise time shorter than the fall time or a second current having an opposite sign to the first current and having a rise time longer than the fall time to the transmission coil;
A step of inducing an electromotive force in the receiving coil based on the current output to the transmitting coil;
Filtering the electromotive force induced in the receiving coil by a filter circuit;
Integrating the current output by the filter circuit with an integrating circuit.
The receiving apparatus according to the fifth aspect of the present invention is:
Depending on the input digital data, either the first current whose rise time is shorter than the fall time or the second current whose rise time is longer than the fall time and in the opposite direction to the first current is selected. A receiving coil in which an electromotive force is induced by flowing the current through the transmitting coil;
A filter circuit for filtering an electromotive force induced in the receiving coil;
An integrating circuit for integrating the current output by the filter circuit,
When the difference between the input voltage to itself and the average value thereof is equal to or greater than a predetermined threshold, the filter circuit outputs a current that outputs a current having a strength corresponding to the difference between the input voltage to the self and the average value. To do.
The receiving apparatus according to the sixth aspect of the present invention is:
Depending on the input digital data, either the first current whose rise time is shorter than the fall time or the second current whose rise time is longer than the fall time and in the opposite direction to the first current is selected. A receiving coil in which an electromotive force is induced by flowing the current through the transmitting coil;
A filter circuit for filtering an electromotive force induced in the receiving coil;
An integrating circuit for integrating the current output by the filter circuit,
When the difference between the input voltage to itself and the output voltage of the integration circuit is greater than or equal to a predetermined threshold, the filter circuit has a current having a strength corresponding to the difference between the input voltage to itself and the output voltage of the integration circuit. Is output.

  In the receiving device of the first development form, it is preferable that the filter circuit outputs a current when a difference between an input voltage to the filter circuit and an average value thereof is a predetermined threshold value or more.

  In the receiving device of the second development form, it is preferable that the filter circuit outputs a current when a difference between an input voltage to the filter circuit and an output voltage of the integrating circuit is equal to or greater than a predetermined threshold.

  In the receiving device of the third development form, it is preferable that the filter circuit outputs a current when the input voltage to the filter circuit includes a frequency component having a frequency exceeding a predetermined threshold.

  In the receiving device according to the fourth embodiment, it is preferable that the filter circuit outputs a current having a strength corresponding to a difference between an input voltage to the filter circuit and an average value thereof.

  In the receiving device of the fifth development form, it is preferable that the filter circuit outputs a current having an intensity corresponding to a difference between an input voltage to itself and an output voltage of the integrating circuit.

  In the receiving device of the sixth development form, it is preferable that the filter circuit outputs a current over a predetermined period from a time point when a difference between an input voltage to the filter circuit and an average value thereof exceeds a predetermined threshold value.

  In the receiving device of the seventh development form, it is preferable that the filter circuit outputs a current over a predetermined period from a time point when a difference between an input voltage to itself and an output voltage of the integrating circuit exceeds a predetermined threshold value. .

  In the transmission device according to the eighth development mode, it is preferable that the data transmission circuit outputs either the first current or the second current to the transmission coil in accordance with the value of the received digital data.

  The transmission / reception device of the ninth development form preferably includes the reception device and the transmission device.

The transmission / reception apparatus of the tenth development form is
The reception device includes a comparison circuit that compares the output voltage of the data reception circuit with a predetermined reference voltage and transmits a comparison result to the transmission device;
The transmission device receives the comparison result, and the intensity of the first current and / or the second current generated by the data transmission circuit according to the received comparison result, and / or It is preferable that a control circuit for controlling the number of pulses is provided.

  In a transmission / reception device according to an eleventh embodiment, the comparison circuit has an integrated voltage value obtained when the data transmission circuit outputs either the first current or the second current a predetermined number of times. It is preferable to compare the reference voltage.

  In a transmission / reception device according to a twelfth embodiment, the control circuit causes the integrated voltage value when either one of the first current and the second current is output N-1 times by the data transmission circuit. Is less than the reference voltage and is output N times, the integrated voltage value exceeds the reference voltage, or when the current is output N-1 times by the data transmission circuit, the integrated voltage value is When the integrated voltage value exceeds the reference voltage and is output N times below the reference voltage, the increment of the integrated voltage value per output of the current divides the absolute value of the reference voltage by N. It is preferable to estimate that it is equal to

  In a thirteenth expansion mode transmission / reception device, when the control circuit cannot obtain a predetermined resolution in the voltage output by the data reception circuit, the first current generated by the data transmission circuit, It is preferable to reduce the second current amount.

  It is preferable that the filter circuit according to the fourteenth development further includes a capacitor connected to the input node and the first node.

The transmission / reception method of the fifteenth development form is
Comparing the voltage output by the integration circuit with a predetermined reference voltage;
Preferably, the method includes a step of controlling the intensity of the first current and / or the second current and / or the number of pulses according to the result of the comparison.

  The present invention eliminates the need for an amplifier circuit for converting a minute induced electromotive force into a digital signal in the receiving apparatus. Therefore, the area and power consumption of the receiving device are reduced.

  In addition, since all the circuits operate asynchronously, a synchronization (clock) signal for sampling input data in the receiving apparatus is also unnecessary. Furthermore, since the output voltage of the integration circuit can be subtracted as well as added, it is possible to generate an output voltage lower than the previous output voltage by subtraction without using a reset signal as in the prior art. it can.

  Further, by using a filter circuit using a bipolar diode whose input bias is always an output bias, a wide output range from the ground to the power supply voltage can be obtained.

  Further, the configuration including the comparison circuit can compensate for the value of the output DC voltage even when there is a variation in the intensity of the transmission current and the reception circuit.

It is a block diagram which shows the structure of the receiver which concerns on the 1st Embodiment of this invention. It is a block diagram which shows the structure of the transmission / reception apparatus which concerns on 1st Example of this invention. It is a timing chart which shows operation | movement of the transmission / reception apparatus which concerns on 1st Example of this invention. It is a block diagram which shows the structure of the filter circuit and integration circuit in the transmission / reception apparatus which concerns on 1st Example of this invention. It is a timing chart which shows operation | movement of the filter circuit and integration circuit in the transmission / reception apparatus which concerns on 1st Example of this invention. It is a timing chart which shows operation | movement of the filter circuit and integration circuit in the transmission / reception apparatus which concerns on 1st Example of this invention. It is a block diagram which shows the structure of the transmission / reception apparatus which concerns on 2nd Example of this invention. It is a timing chart which shows operation | movement of the transmission / reception apparatus which concerns on 2nd Example of this invention. It is a block diagram which shows the structure of the conventional transmission / reception apparatus. It is a timing chart which shows operation | movement of the conventional transmission / reception apparatus. It is a timing chart which shows operation | movement of the conventional transmission / reception apparatus. It is a circuit diagram which shows the structure of the data transmission circuit in the transmission apparatus which concerns on 1st Example of this invention.

  A receiving apparatus according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing the configuration of the receiving apparatus according to this embodiment.

  Referring to FIG. 1, the receiving device 12 includes a receiving coil 107, a filter circuit 104, and an integrating circuit 105. An electromotive force is induced in the reception coil 107 by the transmission coil 106. In the filter circuit 104, when the first current shorter than the fall time is induced by flowing the first current through the transmission coil, the filter circuit 104 is longer in the reverse direction than the first current. The transmission characteristics with respect to the electromotive force are different from those induced by flowing a second current through the transmission coil. The integration circuit 105 integrates the current output from the filter circuit 104.

  A transceiver according to a first embodiment of the present invention will be described with reference to the drawings.

  FIG. 2 is a block diagram showing the configuration of the transmitting / receiving apparatus according to the first embodiment of the present invention. Referring to FIG. 2, the transmission / reception device includes a transmission device 11 and a reception device 12. The transmission device 11 includes a data transmission circuit 101 and a transmission coil 106. The receiving device 12 includes a data receiving circuit 102 and a receiving coil 107.

  The data transmission circuit 101 receives digital data to be transmitted, and outputs a current to the transmission coil 106 according to the value of the received digital data. The data receiving circuit 102 outputs a DC voltage according to the received data. The data reception circuit 102 includes an amplification circuit 103, a filter circuit 104, and an integration circuit 105.

  FIG. 3 is a timing chart for explaining the operation of the transmission / reception apparatus according to the present embodiment. First, the data transmission circuit 101 selects either the first current or the second current according to the input digital data. Here, the first current is positive in the first period in which the rise time is short and the time differential dI / dt of the current is large, and in the second period in which the fall time is long and the absolute value of dI / dt is small. Current flowing through the On the other hand, the second current is a current that flows in a negative direction in the second period having a long rise time, the first period having a short fall time, and the second period having a long rise time. The first current or the second current selected by the data transmission circuit 101 is supplied to the transmission coil 106, and an induction magnetic field is generated by electromagnetic induction.

  An induced electromotive force is generated in the receiving coil 107 by the induced magnetic field. As shown in FIG. 3, the induced electromotive force generated by the first current is a high positive voltage (having a large absolute value) corresponding to the dI / dt of the current in the first period, and the current in the second period. It consists of a low negative voltage (small absolute value) corresponding to dI / dt. On the other hand, the induced electromotive force generated by the second current depends on a high negative voltage (a large absolute value) corresponding to the current dI / dt in the first period and the current dI / dt in the second period. It consists of a very low (small absolute value) positive voltage.

  The amplifier circuit 103 amplifies the induced electromotive force and outputs it. The filter circuit 104 outputs a current only when the difference between the voltage output by the amplifier circuit 103 and the average voltage is a certain value or more. In the case of the first current, the filter circuit 104 blocks a negative voltage having a small difference from the average voltage and allows only a part of the positive voltage to pass. On the other hand, in the case of the second current, the filter circuit 104 blocks a positive voltage having a small difference from the average voltage and allows only a part of the negative voltage to pass.

  The integration circuit 105 integrates the current output from the filter circuit 104. When the output current of the filter circuit 104 based on the first current is input once, the integration circuit 105 increases the output voltage by a minute amount Vp. On the other hand, when the output current of the filter circuit 104 based on the second current is input once, the integration circuit 105 decreases the output voltage by a minute amount Vm.

  FIG. 4 is a block diagram illustrating configurations of the filter circuit 104 and the integration circuit 105 in the transmission / reception apparatus according to the present embodiment. Referring to FIG. 4, the filter circuit 104 includes a capacitor 301, a bidirectional diode 302, a unity gain buffer 303, and a resistor 304. The bidirectional diode 302 is configured by short-circuiting the anode side and the cathode side of two diodes having a logic threshold value Vd in reverse. In the unity gain buffer 303, the input voltage and the output voltage are always equal.

  5 and 6 are timing charts showing operations of the filter circuit 104 and the integration circuit 105. FIG. The filter circuit 104 blocks an output voltage of the amplifier circuit 103 whose absolute value is equal to or less than a certain value. When the input voltage is higher than the logic threshold of the diode as compared with the output voltage, a positive current flows from the input to the output in the filter circuit 104 (FIG. 5). On the other hand, when the input voltage is lower than the output voltage by a logical threshold value of the diode, a negative current flows from the output to the input in the filter circuit (FIG. 6). Furthermore, when the voltage difference between the input voltage and the output voltage is less than or equal to the logic threshold value of the diode, no current flows in the filter circuit 104.

  The capacitor 301, the unity gain buffer 303, and the resistor 304 form a bias conversion circuit. When the output voltage of the filter circuit 104 is Vout, the output Vc of the capacitor 301 is Vout + ΔVx when the voltage of the input signal is higher than the average voltage of the input signal by ΔVx. Next, when the output Vout is lower than the input Vc by Vd or more, that is, ΔVx> Vd, a current flows through the bidirectional diode 302 in the positive direction from the input to the output, and the output Vout is increased by the integration circuit 105. To do. Further, when the output Vout is higher than the input Vc by Vd or more, that is, ΔVx <−Vd, a current flows through the bidirectional diode 302 in the positive direction from the output to the input, and the output Vout is reduced by the integration circuit 105. To do. On the other hand, when the voltage difference between Vout and Vc is Vd or less, no current flows through the bidirectional diode 302. The filter circuit 104 is characterized in that the output current does not depend on the value of the output voltage and is determined only by Vd and ΔVx.

  Note that the filter circuit 104 may be configured without the capacitor 301. In this case, the filter circuit 104 outputs a current when the difference between the input voltage to itself and the output voltage of the integrating circuit 105 is equal to or greater than the logic threshold of the diode.

  By using the filter circuit 104, Vp when the first current is input once and Vm when the second current is input once are constant values independent of Vout. Therefore, when the first current is input N times and the second current is input M times, Vout increases by N * Vp−M * Vm.

  With the transmission / reception apparatus according to the present embodiment, the output voltage can be increased or decreased only by simple amplification and filter processing without digitally converting a minute induced electromotive force input to the data receiving circuit 102. Therefore, the area and power consumption of the data receiving circuit 102 can be reduced. In addition, since the data receiving circuit 102 does not require a synchronous clock signal for sampling data, the trouble of separately inputting a clock is also eliminated. Further, by using two types of transmission currents (first current and second current), not only the output signal level of the integrating circuit can be added but also subtracted. Therefore, Vout lower than the previous Vout can be generated by subtraction without using a reset signal as in the conventional transmitter / receiver.

  FIG. 12 shows a data transmission circuit 101 of the transmission apparatus 11 according to the present embodiment as an example. The following method can be used to generate the first current and the second current. Referring to FIG. 12, the PMOS in the input drivers 603 and 604 is turned on by increasing the PMOS driving power in the input drivers 603 and 604 of the H-bridge type current driving circuit 602 and reducing the NMOS driving power. The rising or rising current transition time can be shortened in the first period, and the rising or rising current transition time can be increased in the second period in which the NMOS of the input drivers 603 and 604 is turned on.

  A transmitting / receiving apparatus according to a second embodiment of the present invention will be described with reference to the drawings. In the first embodiment, the output voltage rise Vp when the first current is input once changes depending on the communication distance and the variation in the logical threshold value Vd of the bidirectional diode 302. The same applies to the drop Vm of the output voltage when the second current is input once. Therefore, it is necessary to provide compensation means so as to correct the change and always provide the intended output voltage.

  The transmission / reception apparatus of this embodiment provides such compensation means. FIG. 7 is a block diagram illustrating the configuration of the transmission / reception apparatus according to the present embodiment. Referring to FIG. 7, the transmission / reception device includes a transmission device 21 and a reception device 22. The transmission device 21 includes a data transmission circuit 101, a transmission coil 106, a reception coil 117, a comparison result reception circuit 503, and a control circuit 504. The reception device 22 includes a data reception circuit 102, a reception coil 107, a comparison circuit 501, a comparison result transmission circuit 502 and a transmission coil 116.

  The data transmission circuit 101 and the data reception circuit 102 are the same as those in the transmission / reception apparatus according to the first embodiment (FIG. 2). The comparison circuit 501 compares the output voltage of the data reception circuit 102 with a predetermined reference voltage Vref. The comparison result transmission circuit 502 feeds back the comparison result of the comparison circuit 501 to the transmission device 21. The control circuit 504 controls the communication intensity and the number of transmission pulses of the data transmission circuit 101 according to the comparison result. Here, as the reference voltage Vref, an appropriate value within the range from the ground to the power supply voltage may be generated inside the receiving device 22 or may be input from the outside of the receiving device 22.

  FIG. 8 is a timing chart illustrating the operation of the transmission / reception apparatus according to the present embodiment. First, the output voltage Vout is set to the lowest level (for example, 0). This can be realized by outputting the second current an appropriate number of times. Next, the first current is input once, the output result Vout of the data receiving circuit 102 is compared with the reference voltage Vref, and the comparison result is transmitted to the control circuit 504.

  When the first current is input Nr-1 times, the output result of the data receiving circuit 102 is lower than the reference voltage Vref, and when the first current is input Nr times, the output result of the data receiving circuit 102 is the reference voltage. When the voltage exceeds Vref, the control circuit 504 estimates that the relationship between the reference voltage Vref and the output voltage increase Vp when the first current is input once is Vp = Vref / Nr.

  Similarly, the control circuit 504 can also estimate the value of Vm. First, the output result Vout of the data receiving circuit 102 is set to the highest level (for example, the power supply voltage Vdd). This can be realized by outputting the first current an appropriate number of times. Next, the second current is input once, the output result of the receiving circuit is compared with the reference voltage Vref, and the result is transmitted to the control circuit 504.

  When the second current is input Nf-1 times, the output result of the receiving circuit exceeds the reference voltage Vref, and when the second current is input Nf times, the output result of the receiving circuit is lower than the reference voltage. The control circuit 504 estimates that the relationship between the reference voltage Vref and the output voltage decrease Vm when the second transmission current waveform is input once is Vp = (Vdd−Vref) / Nf.

When it is desired to set the output voltage of the data receiving circuit 102 to the predetermined value Vo, the control circuit 504 includes the Vp and Vm estimated as described above and the following equation Vo = (input of the first current). Number of times) * Vp- (number of times of second current input) * Vm
The number of times of inputting the first current and the number of times of inputting the second current are determined based on the above.

  If the expected voltage resolution at the output voltage Vout cannot be obtained because the values of Vp and Vm are too large, the values of Vp and Vm are reduced by reducing the intensity of the transmission current of the data transmission circuit 101. Can be small. Here, the values of Vp and Vm when the transmission current is lowered can be calculated by performing the above correction again after lowering the transmission current. As a method of reducing the transmission current of the data transmission circuit 101, a method of reducing the power supply voltage of the data transmission circuit 101, a method of switching the drive current by adjusting the size of the transistor that drives the data transmission circuit 101, or the like can be considered. As described above, the voltage resolution of the output voltage of the data receiving circuit 102 can be improved.

  The transmission / reception apparatus according to the present embodiment can correctly control the value of the output voltage of the data reception circuit 102 even when the intensity of the transmission current and the variation of the data reception circuit 102 occur. Furthermore, since the transmission / reception apparatus according to the present embodiment does not require a correction circuit in the data reception circuit 102, the circuit configuration is simple and an increase in the area of the data reception circuit 102 can be prevented. In addition, since the comparison circuit 501 and the comparison result transmission circuit 502 can also be asynchronous circuits that do not use a clock, the reception device 22 does not need a clock signal and a reset signal.

  It should be noted that the present invention is not limited to the above-described embodiments, and it is obvious that the embodiments can be appropriately changed within the scope of the technical idea of the present invention.

11, 21, 111 Transmitters 12, 22, 112 Receivers 101, 201 Data transmission circuit 102, 202 Data reception circuit 103 Amplification circuit 104 Filter circuit 105 Integration circuits 106, 116, 206 Transmission coils 107, 117, 207 Reception coil 301 Capacitor 302 Bidirectional diode 303 Unity gain buffer 304 Resistance 501 Comparison circuit 502 Comparison result transmission circuit 503 Comparison result reception circuits 504 and 601 Control circuit 602 H-bridge type current drive circuits 603 and 604 Input driver

Claims (11)

Depending on the input digital data, either the first current whose rise time is shorter than the fall time or the second current whose rise time is longer than the fall time and in the opposite direction to the first current is selected. a receiver coil electromotive force is induced by passing the transmission coil or,
A filter circuit for filtering an electromotive force induced in the receiving coil;
An integrating circuit for integrating the current output by the filter circuit,
When the difference between the input voltage to itself and the average value thereof is equal to or greater than a predetermined threshold, the filter circuit outputs a current that outputs a current having a strength corresponding to the difference between the input voltage to the self and the average value. A receiving device. Depending on the input digital data, either the first current whose rise time is shorter than the fall time or the second current whose rise time is longer than the fall time and in the opposite direction to the first current is selected. A receiving coil in which an electromotive force is induced by flowing the current through the transmitting coil;
A filter circuit for filtering an electromotive force induced in the receiving coil;
An integrating circuit for integrating the current output by the filter circuit,
When the difference between the input voltage to itself and the output voltage of the integration circuit is greater than or equal to a predetermined threshold, the filter circuit has a current having a strength corresponding to the difference between the input voltage to itself and the output voltage of the integration circuit. and it outputs the receiving apparatus. The receiving device according to claim 1 , wherein the filter circuit outputs the current having the intensity over a predetermined period from a time point when a difference between an input voltage to the filter and an average value thereof exceeds a predetermined threshold value. The receiving apparatus according to claim 2 , wherein the filter circuit outputs the current having the intensity over a predetermined period from a time point when a difference between an input voltage to itself and an output voltage of the integrating circuit exceeds a predetermined threshold. A transmission coil for inducing an electromotive force in the reception coil by electromagnetic induction;
Depending on the input digital data, either the first current whose rise time is shorter than the fall time or the second current whose rise time is longer than the fall time and in the opposite direction to the first current is selected. a transmitting device having a data transmission circuit for outputting to the transmitting coil or,
A transmission / reception apparatus comprising: the reception apparatus according to claim 1 . The reception device includes a comparison circuit that compares the output voltage of the data reception circuit with a predetermined reference voltage and transmits a comparison result to the transmission device;
The transmission device receives the comparison result, and the intensity of the first current and / or the second current generated by the data transmission circuit according to the received comparison result, and / or The transmission / reception apparatus according to claim 5 , further comprising a control circuit that controls the number of pulses. The comparison circuit, one of the current of the first current or the second current is compared with the reference voltage and the integral voltage value when output a predetermined number of times by the data transmission circuit, according to claim 6. The transmission / reception device according to 6 . The control circuit outputs N times when the integrated voltage value is less than the reference voltage when either the first current or the second current is output N-1 times by the data transmission circuit. When the integrated voltage value exceeds the reference voltage, or when the current is output N-1 times by the data transmission circuit, the integrated voltage value exceeds the reference voltage and is output N times. when the integral voltage value when it falls below the reference voltage, and estimates the increment of the integral voltage value once per output of the current is equal to the absolute value of the reference voltage divided by N, claims 8. The transmission / reception device according to 6 or 7 . The control circuit, when a predetermined resolution is not obtained in the voltage output by the data receiving circuit, the first current and / or the second current amount generated by the data transmitting circuit. The transmission / reception apparatus according to any one of claims 6 to 8 , wherein The filter circuit includes a first diode and a second diode having a predetermined logic threshold, the cathode of the first diode is connected to the anode and the first node of the second diode, and A bidirectional diode having an anode of a first diode connected to a cathode of the second diode and an output node;
A unity gain buffer in which the input voltage and the output voltage are equal, and one of the inputs is connected to the output node and the output is connected to the second node;
The receiving device according to claim 2 , further comprising: a resistor connected to the first node and the second node. The filter circuit includes a first diode and a second diode having a predetermined logic threshold, the cathode of the first diode is connected to the anode and the first node of the second diode, and A bidirectional diode having an anode of a first diode connected to a cathode of the second diode and an output node;
A unity gain buffer in which the input voltage and the output voltage are equal, and one of the inputs is connected to the output node and the output is connected to the second node;
A resistor connected to the first node and the second node;
And a capacitor connected to said first node and said input node, the receiving apparatus according to claim 1.

Images