JPH11289247A - Potential conversion circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a potential conversion circuit for controlling a signal processing circuit to be driven by an oscillator power supply by a logical signal outputted from a signal processing circuit to be driven by a fixed potential power supply. SOLUTION: The potential conversion circuit is provided with a 1st potential comparator 1 to be driven by an oscillation power supply a 2nd potential comparator 2 and an order discriminating circuit 3 for receiving outputs from the 1st and 2nd potential comparators 1, 2 and processing timewise order information when the logical states of outputs from the two potential comparators 1, 2 are transited and constituted so that a 1st logical information signal inputted to the 2nd signal processing circuit is applied to the comparator 1, a 2nd logical information signal is applied to the comparator 2, a result obtained by processing the output change information of the comparators 1, 2 by the circuit 3 is outputted as a logical output 10, and the logical output 10 is controlled by the logical information of the 2nd signal processing circuit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a signal processing circuit for oscillating power supply operation which operates with an oscillating power supply whose electric potential oscillates with respect to the ground, and that the oscillating power supply has a more gradual or steady change in ground potential. A logic signal for controlling a scanning line driver of a liquid crystal display device which performs a time-division matrix display, particularly in a configuration and usage of a potential conversion circuit or a level shifter circuit for exchanging a logic signal between signal processing circuits operating with a potential. The propagation method.

[0002]

2. Description of the Related Art Hitherto, a high driving voltage of 50 V to 150 V has been required for driving a display element or an actuator element, which makes it difficult to integrate a driving circuit into an integrated circuit or increases the cost due to an increase in chip area. I was However, by employing the swing power supply driving method, a technology for reducing the operating voltage of the semiconductor integrated circuit to about half has been developed, and the integration into an integrated circuit has been facilitated, and the cost has been reduced. Here, it is desirable to use a control signal generated by a low-voltage logic circuit as a control signal for controlling the drive circuit using the oscillating power supply from the viewpoint of ease of use. Here, in order to control a signal processing circuit using an oscillating power supply with a low-voltage control signal, it is necessary to use a potential conversion circuit corresponding to the oscillating power supply. First, a swing power supply will be described, and then a conventional example of a potential conversion circuit will be described.

FIG. 6 is a timing chart of a scanning line driver of a liquid crystal display device for performing a matrix display of a time division number n. The scanning line driver uses a row scanning clock LP (Line
Pulse) and a control signal FLM (F
(first line marker), the scanning signals are sequentially output to the scanning line outputs S1 to Sn for n rows. In general, an alternating drive in which the pulse polarity of the output scanning signal is inverted for each row in order to prevent polarization due to application of a direct current component to the liquid crystal element. Here, the potential of the positive pulse is V1, the potential of the negative pulse is V4, and the scanning line potential at the time of selecting the ratio is VM. A positive pulse is always output when an odd scan line is selected, and a negative pulse V4 is output when an even scan line is selected. In the case of a liquid crystal display device of about 640 divisions, about 50 V is applied between V1 and V4, and VM is 25
Since the voltage is normally set to about V, the maximum voltage handled by the scanning line driver is required to be as high as 50 V, which is a considerably high withstand voltage. However, looking closely at the period in which the odd-numbered scanning lines are selected, the highest potential of all the scanning line outputs is V1 and the lowest potential is VM. On the other hand, the maximum potential is VM and the minimum potential is V4 also during the period in which the even-numbered scanning line is selected. Therefore, it can be seen that the withstand voltage that the drive circuit itself really needs can operate at a potential between V1 and VM or a potential between VM and V4. Therefore, power supplies VDD and VSS that swing in a rectangular or trapezoidal shape with respect to the ground potential are used. Oscillating power supply V
In the period in which a positive pulse is required for the scanning line output, DD swings the swing power supply to the high potential side and becomes equal to V1. On the other hand, during the period in which a negative pulse is required, the swing power supply is swung to the lower potential side and V4
To match. At this time, the potential between VDD and VSS is always kept constant, and the high potential level of the logic signal for controlling the row driver is V2, the constant potential level is V3, and the VSS when swinging to the high potential side is V3. , VDD when swinging to the lower potential side is made equal to V2. Such oscillation power supplies VDD and VSS are prepared, and the scanning line driver operates using the oscillation power supplies VDD and VSS as power supplies.
That is, VDD is output to the scanning line output during the odd scanning line selection period requiring a positive pulse, VSS is output to the scanning line output during the even scanning line selection period requiring a negative pulse, and VM is output during the other non-selection periods. The scanning line driver itself handles the potentials of V1 to V3 or V2 to V4, and the scanning line driver outputs V1 to V1.
V4 potential can be supplied. By using such a swing power supply, the withstand voltage required for the drive circuit can be reduced to about half.

FIG. 7 shows a potential relationship required for a potential conversion circuit corresponding to a swing power supply. The line pulse LP and the first line marker are control signals for externally controlling the scanning line driver, and have logical levels of a high potential side V2 and a low potential side V3. In contrast, the swing power supply VD
LP and LPM need to be converted to LP 'and FLM', respectively, inside the scanning line driver operating at D and VSS. During the period when the swing power supply swings to the high potential side, the high potential side level V2 of the control signal is changed to V1. Conversely, during the period when the swing power supply swings to the low potential side, the low potential side level V3 of the control signal is changed.
Needs to be changed to V4 depending on the swing state.

[0005]

In order to input a control signal to the logic circuit of the swing power supply operation, a large amplitude signal having the same maximum potential and the lowest potential of the logic circuit as viewed from the ground level of the swing power supply operation is used. It is technically possible to create a fixed power supply circuit outside the swing power supply circuit and connect it to the input terminal of the swing power supply current circuit. However, in the structure of a normal IC, if the output signal potential of the external level conversion circuit is not between the power supply potentials of the integrated circuit of the swing power supply operation, the protection circuit of the swing power supply operation IC is activated, and the current consumption increases. Is generated. High voltage power supply and high voltage operation logic amplitude amplification that output the logic amplitude from the highest power supply to the lowest power supply of the oscillating power supply even if the current increase in the protection circuit is prevented by addressing the protection circuit current increase problem Circuits are required, which results in increased power consumption and increased circuit costs. When the oscillating potential changes in a pulsed or trapezoidal shape, a method of forming a logic potential level conversion circuit of a constant potential power supply operation at a high potential phase or a low potential phase where the logic value potential does not change can be used. However, it is not easy to configure a simple circuit for transmitting information from the logic level of the fixed potential system to the logic level of the fluctuating potential system or transmitting without noise in the reverse direction during the phase in which the oscillating potential is fluctuating.

[0006]

In order to achieve the above object, a potential conversion circuit according to the present invention comprises an oscillating power supply circuit in which a ground potential is oscillated while maintaining a constant potential difference, and a constant potential power supply in which a ground potential is constant. And a second signal processing circuit operating with a constant potential power supply having a constant ground potential. The second signal processing circuit has a constant potential The first logic information including a power supply and a ground potential is transmitted to the first signal processing circuit, and the first signal processing circuit having a dual power supply structure is provided with a first potential comparison circuit operated by an oscillating power supply. A circuit, a second potential comparator, an output of the first potential comparator and an output of the second potential comparator, and the outputs of the two potential comparators change from a logic state to a logic state inverted from a certain logic state A sequence discriminating circuit for detecting a temporal sequence at the time of transition, and the second signal When a logic information signal input to the logic circuit is applied to the first potential comparison circuit, a logic information signal having a polarity opposite to that of the logic information signal is applied to the second potential comparison circuit, and when the swing power supply swings, A logic output based on the result of detection by the order discrimination circuit of the order of the potential change of the potential comparison circuit, and controlling the logic output by a logic signal of the second signal processing circuit when the swing power supply swings. It is characterized by having.

Further, the potential conversion circuit of the present invention is the first of a double power supply operation having both an oscillating power supply circuit in which a ground potential oscillates while maintaining a constant potential difference and a constant potential power supply circuit having a constant ground potential. A signal processing circuit, and a second signal processing circuit that operates with a constant potential power supply having a constant ground potential, the second signal processing circuit stores first logic information including a constant potential power supply and a ground potential. Logic information is transmitted to the first signal processing circuit, and the signal processing circuit having the first multiple power supply structure includes a first potential comparison circuit for oscillating power supply operation, a second potential comparison circuit, Sequence discrimination for receiving the output of one potential comparison circuit and the output of the second potential comparison circuit, and detecting the temporal sequence when the outputs of the two potential comparison circuits transition from one logic state to an inverted logic state And a logic information signal input to the second signal processing circuit. The first potential comparison circuit is provided with a logic information signal having a polarity opposite to that of the logic information signal to the second potential comparison circuit, and an inverter circuit having a threshold is used for the first and second potential comparison circuits. The result of the sequence discrimination circuit detecting the order of the output change of the potential comparison circuit when the oscillating power supply oscillates is used as a logical output, and when the oscillating power supply oscillates, the logic signal of the second signal processing circuit is used. A structure for controlling the logical output is provided.

Further, in the potential conversion circuit according to the present invention, the first signal processing circuit is formed on the same semiconductor integrated circuit chip, and information is input from the externally provided second signal processing circuit to oscillate. It is characterized in that the potential is converted into logic information composed of a power supply potential and the first signal processing circuit is controlled.

Considering the ground potential, the comparison potential of the potential comparator when the swing power supply swings to the higher potential side is set higher than the high potential level of the input logic signal, and conversely, the swing power supply becomes lower. If the comparison potential of the potential comparison circuit when swinging to the potential side is set lower than the low potential level of the input logic signal, the logic signal to be input when the swing power supply swings to the high potential side or low potential side Always cross the comparison potential. When the oscillating power supply oscillates from the high potential side to the low potential side, the potential comparison circuit in which the logic value of the input signal is at the high potential level crosses the comparison potential first, and the one at the low potential level Later it will cross the comparison potential. Conversely, when the swing power supply swings from the low potential side to the high potential side, the potential comparison circuit in which the logical value of the input signal is at the low potential level crosses the comparison potential first, and Will later cross the comparison potential. Therefore, it is possible to know the logical value of the input signal when the swing power supply swings by detecting the order of crossing the comparison potential. In addition, since an inverter circuit generally has a threshold value within the voltage range of the operating power supply and outputs a logic signal depending on whether an input signal is higher or lower than the threshold value, an inverter circuit can be used instead of the potential comparison circuit. is there.

[0010]

FIG. 1 shows an embodiment of a potential conversion circuit according to the present invention. This potential conversion circuit comprises two potential comparison circuits 1 and 2 and a sequence discrimination circuit 3. As an input logic signal, an input signal 4 having a logic value of two states of a high potential level and a low potential level and an input signal 7 of an inverted logic thereof are used. The potential comparison circuit 1 compares the non-inverted input signal 4 with the comparison potential 5 and outputs a comparison signal 6. The potential comparison circuit 2 compares the inverted input signal 7 with the comparison potential 8 and outputs a comparison signal 9. The sequence discriminating circuit 3 receives the comparison signals 6 and 9, processes the sequence information whose logic state changes when the power supply fluctuates, and outputs a logic output signal 10. The potential conversion circuits 1 and 2, the sequence discrimination circuit 3, and the comparison potential generators 11 and 12 all operate on a swing power supply. The oscillating power supply oscillates with respect to the ground potential, but the power supply potential is constant from the viewpoint of a circuit operating with the oscillating power supply. Conversely, the constant potential of the circuit operating with the oscillating power supply will oscillate together with the oscillating power supply when viewed from the ground potential. Here, the comparison potentials 5 and 8 are higher than the high potential level of the input logic signal when the oscillating power supply oscillates to the high potential side and the oscillating power supply oscillates to the low potential side when viewed from the ground potential. It is set lower than the low potential level of the input logic signal when it operates. Here, a voltage comparator including a differential amplifier can be used as the potential comparison circuit. Also,
If an inverter circuit having a threshold value, for example, an inverter circuit using a complementary field effect transistor pair is used,
It can also be used as a potential comparison circuit that uses the threshold as a comparison potential. In this case, the comparison potential can be adjusted within the voltage range of the operation power supply by adjusting the on-resistance of the transistor pair.

FIG. 3 is a timing chart showing the operation of the present potential conversion circuit. The swing power supply fluctuates with respect to ground potential,
VDD and VSS of the swing power supply become the potentials V1 and V3 when the high potential swings, and V2 and V4 when the low potential swings. V1
The potential between V3 and V2 and the potential between V2 and V4 are always kept constant. Here, the timing diagram is drawn based on the ground. The high potential level of the logic signal input to the potential conversion circuit matches V2, and the low potential level matches V3. The non-inverted input signal 4 is initially at a high potential level, and thus the inverted input signal 7 is at a low potential level. The comparison potentials 5 and 8 are selected to be higher than the potential V2 when the swing power source swings at a high potential and higher than the potential V3 when the swing power source swings, but are constant when viewed from inside the swing power source. That is, the swing power supply VS
The potential difference between S and the comparison potentials 5 and 8 is constant. Here, the comparison potentials 5 and 8 may be changed according to the phase of the oscillating power supply if the above conditions are satisfied. Although the level of the input logic signal and the level of the oscillating power supply are matched at V2 and V3, different potentials may be used as long as the comparison potential satisfies the above condition. Although the same potential is used for the comparison potentials 5 and 8, different potentials may be used as long as the above conditions are satisfied.

The operation of the potential conversion circuit under the above-described swing power supply, input signal, and comparison power supply will now be described. The potential comparison circuit outputs a low potential level L when the input signal is higher than the comparison potential, and outputs a high potential level H when the input signal is low. The logic level here is a logic level operating in the swing power supply, not a logic level of the input signal. First, at time T0, the non-inverted signal is at the high potential level and the swing power supply swings to the high potential side. At this time, the potential comparison circuit 1
Outputs the L level. When the oscillating power supply oscillates to the lower potential side at time T1, the input signal crosses the comparison potential, so that the comparison output 6 transitions to the H level. At time T4, the comparison is made again when the oscillating power supply returns to the higher potential side. The comparison output returns to the L level across the potential. Thus, the output of the comparison output 6 changes in synchronization with the swing. Next, looking at the inversion signal side, the comparison output 9 of the potential comparison circuit 2 transitions to the H level at time T0 slightly later than the former at time T2, and conversely at time T5 at time T0. Return to L level early. Next, since the input signals are inverted at time T3, the comparison output 6 on the non-inversion input side transitions to the H level slightly later than the comparison output 9 on the inversion side at time T4, and changes to L level earlier at time T5. Transition to a level. In other words, when the swing power supply swings to the lower potential side, the input to which the comparison output transitions first is at the high potential level, and when the swing power supply swings to the higher potential side, the input to which the comparison output transitions first is higher. Is detected at the low potential level, and this is discriminated by the sequence discriminating circuit 3 described below to obtain the logical output 10. Here, the comparison output uses the L level when the input signal is higher than the comparison potential, and uses the H level when the input signal is lower than the comparison potential. Either positive logic or negative logic may be used.

Next, an embodiment of the sequential discrimination circuit will be described with reference to FIG. The sequence discriminating circuit is a set / reset type flip-flop 20 using a NAND gate.
And a combination circuit 21 for generating a set input 22 and a reset input 23 thereof. The combination circuit has a comparison output 6 on the non-inverting input side and a comparison output 9 on the inverting input side.
To generate a set signal and a reset signal. When both the comparison outputs 6 and 9 are at the L or H level, the set signal and the reset signal are both at the H level, and the flip-flop is in the holding state. FIG. 2 shows the set input 22, the reset input 23, and the output 10 of the sequence discriminating circuit. First, the operation at the time T1 will be described. When both comparison outputs start from L and the comparison output 6 transitions to H first, the set input 22
Becomes L, the comparison output 9 transits to H, the set input returns to H, and the flip-flop is set. At time T4, the comparison output changes in the reverse order, a negative pulse is generated at the reset input, and the reset input is reset. After all, when starting from L, that is, when the swing power supply swings to the lower potential side, it can be detected that the input 4 on the previously changed side was at the higher potential level. Time T when both comparison outputs start from H
When T2 and T5 are considered, when the swing power source swings to the high potential side, it can be detected that the input on the previously changed side was at the low potential level. Although a NAND flip-flop is used in the above embodiment, a NOR flip-flop may be used.

FIG. 4 shows an embodiment in which the potential conversion circuit according to the present invention is used for a scanning line driver of a liquid crystal display device. Scan line driver is timing chart of the conventional example 6
As shown in the figure, normally, the row clock LP and the FLM signal indicating the first row are input, and the scanning pulses are sequentially output to the plurality of scanning line outputs S1 to Sn in synchronization with the fall of LP. In this method, the potential conversion circuit according to the present invention is used only for the FLM signal, and the LP signal is generated inside the scanning line driver using the FLM potential conversion circuit.
The scanning line driver has scanning line outputs from S1 to Sn, and includes a line sequential addressing circuit 42 and an output circuit 43 for sequentially selecting them. A shift register circuit in which latch circuits 41 are connected in series is used as the line sequential addressing circuit. Shift data SD is applied to the data input of the first stage latch, and shift clock CK is applied to the clock input commonly connected to all the stage latches. To shift the shift data and select the selection signals Q1 to Qn.
Output to The output circuit inputs the selected output and the polarity signal POL of the oscillating power supply, outputs the scanning line output potential at the time of non-selection to the unselected scanning line, and outputs the selected scanning line to the selected scanning line in accordance with the oscillating polarity of the oscillating power supply. Outputs a positive or negative pulse to the scan line output. A logic signal of a constant potential power supply operation is used as an input signal for controlling the scanning line driver, a non-inverted input signal FLM and an inverted input signal FLMB are input to the potential conversion circuit 40 according to the present invention, and the output is shifted to a shift register. Data SD
And An inverter circuit composed of a pair of complementary field-effect transistors is used for the potential comparison circuit of the potential conversion circuit, and the circuit shown in FIG. 2 is used for the order discrimination circuit. As the shift clock that should normally use the LP signal, a signal obtained by calculating the logical product of the set signal 22 and the reset signal 23 in the sequence discriminating circuit by the logical product gate 47 is used. In this embodiment, the shift register system is used for the line sequential addressing circuit, but a line sequential addressing circuit of a counter system may be used. Although the shift clock generated here is an exclusive OR signal of the comparison outputs 6 and 9 of the two potential comparison circuits in the potential conversion circuit shown in FIG. 1, an exclusive OR circuit having another configuration may be used. Good.

Next, the operation timing is shown in FIG. The swing power supply VDD / VSS swings from V1 / V3 to V2 / V4, and the scanning line output potential when not selected is VM. The scanning clock is not used because LP is generated inside the scanning line driver in this embodiment, but is shown for reference. The FLM signal indicating the first row becomes H in the second LP. FLMB is its inverted signal. The output 10 of the potential conversion circuit outputs the H level when the oscillating power supply oscillates while the FLM is at the H level, and returns to the L level when the oscillating power supply next oscillates. This is given to the shift data SD of the shift register. On the other hand, the shift clock CK is composed of the logical product of the set signal 22 and the reset signal 23 of the sequence discriminating circuit shown in FIG. 2 and therefore outputs a negative pulse when the oscillating power source oscillates as can be seen from the timing chart 3. By shifting the shift data SD at the rising edge of the shift clock CK, the outputs Q1 to Qn of the line-sequential addressing circuit are sequentially selected, and the scan line outputs S1 to S1 according to the polarity signal POL indicating the state of the oscillating power supply at that time. A positive selection pulse or a negative selection pulse is output to Sn. The shift clock generates a pulse-like signal every time the swing power supply swings like a normal LP signal, and thus can be used instead of the LP signal.

[0016]

The potential conversion circuit according to the present invention can transmit logic information when the swing power supply swings to the swing power supply operation logic circuit. This makes it possible to control the drive waveform of the high-voltage output drive circuit in the swing power supply operation according to the drive information of the external low-constant voltage circuit. With the oscillating power supply configuration, it is possible to obtain a voltage amplitude output larger than the power supply voltage amplitude of the oscillating operation integrated circuit. For example, when the low constant voltage circuit voltage is a 5V logic circuit,
Assuming that the swing power supply voltage is 25 V, the swing voltage is 20 V, the minimum swing positive potential is +5 V, and the maximum swing negative potential is 0 V, the drive IC operating at 25 V can operate from −20 V to +25 V. It is possible to output a drive signal having a logic amplitude of 45v. In addition, since a pulse signal can be generated when the oscillating power supply oscillates, an external signal is supplied to a circuit that operates synchronously when the oscillating power supply oscillates on both the high potential side and the low potential side. Drive control without supplying Further, since the potential conversion circuit of the present invention can be mounted on a semiconductor integrated circuit that operates with a swing power supply, an external circuit is not required, and the cost is reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram of a potential conversion circuit according to an embodiment of the present invention.

FIG. 2 is an example of a circuit of a sequential discrimination circuit according to an embodiment of the present invention.

FIG. 3 is a timing chart of the potential conversion circuit in the embodiment of the present invention.

FIG. 4 is a block diagram showing an application example to a scanning line driver.

FIG. 5 is a timing chart of an application example to a scanning line driver.

FIG. 6 is a timing chart illustrating the operation of the scanning line driver.

FIG. 7 is a diagram illustrating conversion levels required for a potential conversion circuit.

[Explanation of symbols]

1, 2 First and second potential comparison circuit 3 Order discrimination circuit 4, 7 First and second logic information signal 5, 8 First and second comparison potential 6, 9 First and second potential comparison Comparison output of circuit 10 Logical output of potential conversion circuit 20 Set-reset type flip-flop circuit constituting sequence discrimination circuit 21 Set signal and reset signal generation circuit 22 constituting sequence discrimination circuit 22, 23 Set signal and reset signal 40 According to the present invention Potential conversion circuit 41 Data latch circuit forming a line-sequential addressing circuit 42 Line-sequential addressing circuit forming a scanning line driver 43 Scanning line output circuit forming a scanning line driver 47 Logical product gate for generating a shift clock VDD High potential swing Dynamic power supply VSS Low-potential-side swing power supply LP Row line driving scan line driver FLM, FLMB Signal indicating the first row of the scanning line driver and its inverted signal FLM, FLMB Signal indicating the first row of the scanning line driver and its inverted signal SD Shift data input to the SD line sequential addressing circuit CK The line sequential addressing circuit Shift clock to be driven POL Swing polarity signal of oscillating power supply Q1 to Qn Select output of line-sequential addressing circuit S1 to Sn Scan line of scan line driver VM Scan line output potential when non-selected V1 High potential during high potential swing Side swing power supply potential V2 High potential swing power supply potential at low potential swing V3 Low potential swing power supply potential at high potential swing V4 Low potential swing power supply potential at low potential swing LP 'potential LP signal after conversion FLM 'FLM signal after potential conversion

Claims (6)

[Claims] 1. A first signal processing circuit for oscillating power supply operation comprising an oscillating power supply circuit for oscillating a ground potential while maintaining a constant potential difference, and a second signal processing circuit for a constant potential power supply operation with a constant ground potential. Wherein the second signal processing circuit transmits logic information to the first signal processing circuit, and the first signal processing circuit includes a first potential comparison circuit for oscillating power supply operation. And a second potential comparison circuit, and a temporal sequence when the outputs of the first potential comparison circuit and the output of the second potential comparison circuit are input and the logic states of the outputs of the two potential comparison circuits transition. And a sequence discriminating circuit for processing information, the first logical information signal input to the second signal processing circuit is provided to the first potential comparison circuit, the second logical information signal is the second potential The result of processing the output change information of the potential comparison circuit by the order discrimination circuit is provided as a logical output to the comparison circuit. And a potential conversion circuit having a structure for controlling the logical output according to the logical information of the second signal processing circuit. 2. A first signal processing circuit for oscillating power supply operation comprising an oscillating power supply circuit for oscillating a ground potential while maintaining a constant potential difference, and a second signal processing circuit for a constant potential power supply operation with a constant ground potential. Wherein the second signal processing circuit transmits logic information to the first signal processing circuit, and the first signal processing circuit includes a first potential comparison circuit for oscillating power supply operation. And a second potential comparison circuit, and a temporal sequence when the outputs of the first potential comparison circuit and the output of the second potential comparison circuit are input and the logic states of the outputs of the two potential comparison circuits transition. And a sequence discriminating circuit for processing information, the first logical information signal input to the first signal processing circuit is provided to the first potential comparison circuit, the first logical information of the opposite polarity of the first logical information The second logic information signal is supplied to the second potential comparison circuit, and the output of the potential comparison circuit changes when the power supply swings. Is applied to each potential comparison circuit, and the output of the potential comparison circuit processes the temporal order information at the time of transition from one logic state to the inverted logic state. A potential conversion circuit having a structure that outputs and controls the logical output according to logical information of a second signal processing circuit. 3. A first signal processing circuit for oscillating power supply operation comprising an oscillating power supply circuit for oscillating a ground potential while maintaining a constant potential difference, and a second signal processing circuit for constant power supply operation with a constant ground potential. Wherein the second signal processing circuit transmits logic information to the first signal processing circuit, and the first signal processing circuit includes a first potential comparison circuit for oscillating power supply operation. And a second potential comparison circuit, and a temporal sequence when the outputs of the first potential comparison circuit and the output of the second potential comparison circuit are input and the logic states of the outputs of the two potential comparison circuits transition. And a sequence discriminating circuit for processing information, the first logical information signal input to the second signal processing circuit is provided to the first potential comparison circuit, the first and second potential comparison circuit, A second logic information signal to the second potential comparison circuit. A potential conversion circuit having a structure in which a result obtained by processing the output change information of the potential comparison circuit by the order discriminating circuit is used as a logical output and the logical output is controlled by the logical information of the second signal processing circuit. 4. A first signal processing circuit for oscillating power supply operation comprising an oscillating power supply circuit for oscillating a ground potential while maintaining a constant potential difference, and a second signal processing circuit for a constant potential power supply operation with a constant ground potential. Wherein the second signal processing circuit transmits logic information to the first signal processing circuit, and the first signal processing circuit includes a first potential comparison circuit for oscillating power supply operation. And a second potential comparison circuit, and a temporal sequence when the outputs of the first potential comparison circuit and the output of the second potential comparison circuit are input and the logic states of the outputs of the two potential comparison circuits transition. And a sequence discriminating circuit for processing information, the first logical information signal input to the first signal processing circuit is provided to the first potential comparison circuit, the first logical information of the opposite polarity of the first logical information The second logic information signal is supplied to the second potential comparison circuit, and the output of the potential comparison circuit changes when the power supply swings. To the respective potential comparison circuits, and the order discrimination circuit sets a logical product of the first comparison output and an inverted signal of the second comparison output as a set signal, and A set-reset flip-flop that performs a logical product of a comparison output and an inverted signal of the first comparison output to generate a set signal, the output of the flip-flop being a logic output of the sequence discrimination circuit, A potential conversion circuit having a structure for controlling the logic output based on logic information of a signal processing circuit. 5. A first signal processing circuit for oscillating power supply operation comprising an oscillating power supply circuit for oscillating a ground potential while maintaining a constant potential difference, and a second signal processing circuit for a constant potential power supply operation with a constant ground potential. Wherein the second signal processing circuit transmits logic information to the first signal processing circuit, and the first signal processing circuit includes a first potential comparison circuit for oscillating power supply operation. And a second potential comparison circuit, and a temporal sequence when the outputs of the first potential comparison circuit and the output of the second potential comparison circuit are input and the logic states of the outputs of the two potential comparison circuits transition. And a sequence discriminating circuit for processing information, the first logical information signal input to the first signal processing circuit is provided to the first potential comparison circuit, the first logical information of the opposite polarity of the first logical information The second logic information signal is supplied to the second potential comparison circuit, and the output of the potential comparison circuit changes when the power supply swings. To the respective potential comparators, and the oscillating power supply oscillates using the exclusive OR of the comparison output of the first potential comparator and the comparison output of the second potential comparator as a logical output. A potential conversion circuit having a structure for controlling the first signal processing circuit by using the logical output generated at the time when the potential conversion is performed. 6. The first signal processing circuit is formed on the same semiconductor integrated circuit chip. Logic information from the second signal processing circuit provided externally is input to the first signal processing circuit to generate logic information comprising a swing power supply potential. 6. The potential conversion circuit according to claim 1, wherein the potential conversion circuit controls the first signal processing circuit.