JP2009200978A - Comparison circuit apparatus, serial interface circuit apparatus, and electronic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide: a comparison circuit apparatus capable of suppressing the occurrence of variation in comparison results, and capable of downsizing without complicating the apparatus; a serial interface circuit apparatus; and an electronic device. <P>SOLUTION: An external resistive element 13 and a current restriction resistive element 21 are provided outside an integrated circuit part 11, and an interior resistive element 14 and a pull-down resistive element 22 are closely formed in the integrated circuit part 11. A resistance value R1 of the resistive element for restricting current, a resistance value R2 of the pull-down resistive element 22, a resistance value R3 of the exterior resistive element, and a resistance value R4 of the interior resistive element satisfy a relation of R1:R2=R3:R4. A reference voltage depending on a divided voltage obtained by dividing a predetermined voltage by the interior resistive element 14 and the exterior resistive element 13 is generated by a reference voltage generating part 15. A voltage generated by the current restriction resistive element 21 and the pull-down resistive element 22, and the reference voltage generated by the reference voltage generating part 15, are compared by a comparing part 16. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a comparison circuit device capable of correcting a voltage level of a reference voltage used for comparison, a serial interface circuit device using the comparison circuit device, and an electronic apparatus.

  FIG. 1 is a circuit diagram showing a configuration of a conventional comparison circuit device 1. The comparison circuit device 1 includes an integrated circuit (IC) section 2 in which a logic fixing resistor 3, that is, a pull-down resistor 3 and a comparator 4 are formed, and a current limiting resistor 5 is integrated. For example, on the substrate outside the circuit unit 2. The current limiting resistance element 5 is connected to, for example, a switch SW that is provided in a vehicle and generates a brake signal. A pull-down resistance element 3 is connected to one input terminal of the comparator 4, and a reference voltage is applied to the other input terminal. In accordance with the opening / closing operation of the switch SW, a current flows from the DC power supply unit to the external resistance element 5 and the pull-down resistance element 3, and the voltage applied to one input terminal of the comparator 4 changes. A signal corresponding to the opening / closing operation of the switch SW is output, and the signal output from the comparator 4 is supplied to, for example, the microcomputer 6 and used for predetermined processing.

  There is a difference in resistance value between the current limiting resistor element 5 connected to the integrated circuit unit 2 and the pull-down resistor element 3 built in the integrated circuit unit 2. This may cause an error in the determination. The variation is about ± 1% in the external resistance element, whereas the variation is about ± 30% in the resistance element built in the IC. For this reason, the input voltage of the comparator 4 determined by the pull-down resistance element 3 varies, and there is a problem that the result of comparison with the reference voltage also varies. For this reason, when accuracy is required for the comparison determination of the comparator 4, it is necessary to change the pull-down resistance element 3 to an external component with little variation in resistance value.

  FIG. 2 is a circuit diagram showing a configuration of the comparison circuit device 7 in which a pull-down resistance element is provided outside the IC. The comparison circuit device 7 has a plurality of input channels, that is, input units 8. The comparator 4 compares the voltage corresponding to the input signal given to each of the plurality of input units 8 with the reference voltage, and compares the comparison results. Output. When accuracy is required for the comparison judgment of the comparator 4, as described above, the pull-down resistance element needs to be changed to an external component with little variation in resistance value. A plurality of comparators 4 are provided in the circuit unit 9, and a pull-down resistance element 3 and a current limiting resistance element 5 are connected to the comparators 4 outside the integrated circuit unit 9. When a plurality of input units 8 are provided in this way, the board area is increased because the pull-down resistance element 3 is mounted, so that it is difficult to reduce the size of the apparatus and increase the cost of the product. There is.

  As a first conventional technique for correcting a reference voltage, a plurality of resistors are connected in series in an A / D converter that converts an analog signal into a digital signal while comparing the magnitude of the input analog signal with a reference signal. The voltage correction that corrects the input reference voltage by using the ladder resistor that draws the divided voltage of the input reference voltage applied to the entire series connection from the connection part between the resistors and the voltage drawn from the ladder resistor. Some have a circuit (see, for example, Patent Document 1).

  In addition, as a second conventional technique for correcting a reference voltage, a reference voltage source that generates a constant reference voltage, and a pseudo cell measurement circuit that measures an on-current of a pseudo cell manufactured in the same process as a memory cell transistor An A / D converter that performs A / D conversion on the output of the pseudo cell measurement circuit, and a reference voltage correction circuit that corrects the output voltage of the reference voltage source based on the output of the A / D converter and outputs the reference voltage as a reference voltage And the reference voltage is corrected (see, for example, Patent Document 2).

JP 2004-213747 A JP 2000-278130 A

  In the first and second conventional techniques, correction is performed by measuring a voltage, and when correcting the reference voltage, a circuit for measuring the voltage is required. When such a measurement circuit is provided, there is a problem that the apparatus becomes complicated. In the first and second conventional techniques, the reference voltage is not corrected in accordance with variations in resistance values of pull-down resistance elements built in the integrated circuit section.

  Accordingly, an object of the present invention is to make it possible to suppress the occurrence of variations in comparison results even when a pull-down resistance element connected to the input terminal of the comparator is formed in an integrated circuit, and to complicate the apparatus. It is an object of the present invention to provide a comparison circuit device, a serial interface circuit device, and an electronic apparatus that can be formed in a small size without any problems.

The present invention (1) is a comparison circuit device that includes an integrated circuit unit and compares a voltage according to an input signal with a reference voltage,
Each provided with a resistance element for current limiting provided outside the integrated circuit part, and a resistance element for pull-down formed in the integrated circuit part and connected in series with the current limiting resistance element, A plurality of input units for generating a voltage according to the input signal;
An external resistance element provided outside the integrated circuit unit;
An internal resistance element connected in series to the external resistance element and formed in the integrated circuit portion in proximity to the pull-down resistance element;
A reference voltage generation unit that is formed in the integrated circuit unit and generates a reference voltage corresponding to a divided voltage obtained by dividing a predetermined voltage by the internal resistance element and the external resistance element;
A comparison unit that compares the voltage generated by the input unit with the reference voltage generated by the reference voltage generation unit and outputs a comparison result;
When the resistance value of the current limiting resistance element is R1, the resistance value of the pull-down resistance element is R2, the resistance value of the external resistance element is R3, and the resistance value of the internal resistance element is R4, R1, R2, R3 and R4 are
R1: R2 = R3: R4
The comparison circuit device is characterized by satisfying the above.

The present invention (5) is a serial interface circuit device comprising the comparison circuit device,
The comparison unit is a serial interface circuit device that selectively compares a voltage generated by any one of a plurality of input units with a voltage generated by a reference voltage generation unit. .

  According to a sixth aspect of the present invention, there is provided an electronic apparatus including the comparison circuit device and performing a predetermined process according to a comparison result of the comparison unit.

  According to the present invention (1), in the process of manufacturing the integrated circuit portion, the resistance value of the pull-down resistance element and the internal resistance element formed in the integrated circuit portion varies from the resistance value in the design stage. Even so, since the pull-down resistance element and the internal resistance element are formed close to each other, the variation from the resistance value in the design stage is almost equal. That is, in the manufacturing process, if the resistance value of the pull-down resistance element is lower than the resistance value at the design stage by a predetermined ratio, the resistance value of the internal resistance element is also lower by a predetermined value than the resistance value at the design stage. If the resistance value of the resistor element becomes higher by a predetermined ratio than the resistance value at the design stage, the resistance value of the internal resistance element also becomes higher by a predetermined ratio from the resistance value at the design stage. External resistance elements provided outside the integrated circuit portion, that is, current limiting resistance elements and external resistance elements have little variation in resistance values.

  The resistance value of the current limiting resistance element is R1, the resistance value of the pull-down resistance element is R2, the resistance value of the external resistance element is R3, the resistance value of the internal resistance element is R4, R1, R2, R3 And R4 are selected so as to satisfy the relation of R1: R2 = R3: R4. Even if R2 and R4 vary from the resistance value in the design stage in the manufacturing process of the integrated circuit portion, the variation of R2 and R4 is almost equal, so the ratio of R2 and R4 is almost unchanged. Therefore, even if R2 varies from the resistance value in the design stage in the manufacturing process, R4 varies in the same manner. Therefore, the divided voltage obtained by dividing the predetermined voltage by the internal resistance element and the external resistance element having a small variation in resistance value reflects the variation in resistance value of the pull-down resistance element. Since the reference voltage generation unit generates the reference voltage according to the divided voltage, it is possible to generate the reference voltage according to the variation in the resistance value of the pull-down resistance element.

  Since the integrated circuit portion is composed of a plurality of chips formed simultaneously on the wafer, the resistance value of the pull-down resistance element may vary depending on the chip or may vary depending on the manufacturing lot, and the reference voltage is fixed. Even if the same input signal is given, the comparison result of the comparison unit differs depending on the integrated circuit unit, but in the present invention, the reference voltage generation unit sets the resistance value of the internal resistance element as described above. Since the corresponding reference voltage is generated, if the same input signal is given, the comparison result of the comparison unit is the same in any integrated circuit unit. Therefore, even if the pull-down resistor element is formed in the integrated circuit portion, the reliability is high, and the substrate is compared with the case where the pull-down resistor element is formed outside the integrated circuit portion in each of the plurality of input portions. The mounting area to be mounted on the substrate can be reduced, the apparatus can be miniaturized, and the number of processes can be reduced when the integrated circuit portion is mounted on the substrate and assembled.

  According to the invention (5), using the comparison circuit device, a voltage generated by any one of the plurality of input units by the comparison unit and a voltage generated by the reference voltage generation unit are obtained. By making a selective comparison, a small and highly reliable serial interface device can be realized.

  According to the present invention (6), by using the comparison circuit device, it is possible to reduce the size of an electronic device that performs a predetermined process using a result of comparison between a voltage corresponding to a plurality of input signals and a reference voltage. it can.

  FIG. 3 is a circuit diagram showing an electrical configuration of the comparison circuit device 10 according to the embodiment of the present invention. The comparison circuit device 10 includes an integrated circuit unit 11 formed by an integrated circuit (IC), and compares a voltage corresponding to an input signal with a reference voltage. The comparison circuit device 10 includes a plurality of input units 12, an external resistance element 13, an internal resistance element 14, a reference voltage generation unit 15, and a comparison unit 16. A reference voltage correction means 17 for correcting the reference voltage is configured including the external resistance element 13, the internal resistance element 14, and the reference voltage generation unit 15.

  Each input unit 12 includes a current limiting resistor element (hereinafter referred to as a current limiting resistor element) 21 and a pull-down resistor element (hereinafter referred to as a pull-down resistor element) 22. The current limiting resistance element 21 is a resistance element that is provided outside the integrated circuit unit 11 and limits a direct current applied to the integrated circuit unit 11. One connection terminal of the current limiting resistance element 21 is connected to an input connection terminal 23 provided in the integrated circuit unit 11, and an input signal is given to the other connection terminal. In the present embodiment, the connection may be either a direct connection or a connection using wiring, as long as it is electrically connected. The integrated circuit unit 11 and the current limiting resistance element 21 are mounted on a printed circuit board.

  The pull-down resistor element 22 is formed in the integrated circuit unit 11 and connected in series with the current limiting resistor element. One connection terminal of the pull-down resistor element 22 is connected to the input connection terminal 23, and the other connection terminal is connected to a ground section 24 provided in the integrated circuit section 11. The other connection terminal of the current limiting resistance element 21 is an input terminal. When an input signal is given to the input terminal, a voltage corresponding to the input signal is generated by the current limiting resistor element 21 and the pull-down resistor element 22. The voltage corresponding to the input signal is a voltage applied to the pull-down resistor element 22.

  The external resistance element 13 is provided outside the integrated circuit section 11, and one and the other connection terminals thereof are connected to connection terminals (hereinafter referred to as connection terminals) 25 and 26 for connecting external resistance elements provided in the integrated circuit section 11. Each is connected. The external resistance element 13 is also mounted on the printed circuit board.

  Each internal resistance element 14 is formed in the integrated circuit unit 11 and is formed close to the pull-down resistance element 22. Here, it is only necessary that the internal resistance elements 14 and the pull-down resistance elements 22 are formed at the integrated positions in the integrated circuit portion 11, and it is more preferable that they are formed adjacent to each other. The internal resistance element 14 is connected to the external resistance element 13 in series. One connection terminal of the internal resistance element 14 is connected to the connection terminal 25, and the other connection terminal is connected to the ground portion 24.

When the resistance value of each current limiting resistance element 21 is R1, the resistance value of each pull-down resistance element 22 is R2, the resistance value of the external resistance element 13 is R3, and the resistance value of the internal resistance element 14 is R4, R1, R2, R3 and R4 are determined so as to satisfy the following relational expression (1).
R1: R2 = R3: R4 (1)

  In the present embodiment, the resistance values of the current limiting resistance elements 21 are determined to be equal and the resistance values of the pull-down resistance elements 22 are determined to be equal, but the resistance values of the current limiting resistance element 21 and the pull-down resistance element 22 are It may be different for each input unit 12 as long as the relationship satisfies the above formula (1).

  The reference voltage generation unit 15 is formed in the integrated circuit unit 11 and generates a reference voltage corresponding to a divided voltage obtained by dividing a predetermined voltage by the internal resistance element 14 and the external resistance element 13. The reference voltage generation unit 15 includes first to sixth resistance elements 31 to 36, first and second operational amplifiers 37 and 38, and a correction circuit unit 39.

  The first, second, and third resistance elements 31, 32, and 33 are connected in series, the first resistance element 31 is connected to the power supply unit (BATT) 41, and the third resistance element 33 is connected to the ground unit 24. The The first to third resistance elements 31 to 33 divide the power supply voltage provided by the power supply unit 41. The resistance values of the first to third resistance elements 31 to 33 are determined by specifications, respectively, and the threshold level in the comparator C is determined by the resistance values of the first to third resistance elements 31 to 33.

  The non-inverting input terminal 43 of the first operational amplifier 37 is connected to the connection portion of the first resistance element 31 and the second resistance element 32. The first operational amplifier 37 is connected to the inverting input terminal 44 and the output terminal 45, and functions as a voltage follower. The output terminal 45 of the first operational amplifier 37 is connected to the power supply unit 41 via the fourth resistance element 34 and also connected to the connection terminal 26. The fourth resistance element 34 is a current limiting resistance element.

  The non-inverting input terminal 46 of the second operational amplifier 38 is connected to the connection site between the second resistance element 32 and the third resistance element 33. The second operational amplifier 38 functions as a voltage follower by connecting the inverting input terminal 47 and the output terminal 48. The output terminal 48 of the second operational amplifier 38 is connected to the power supply unit 41 via the fifth resistance element 35. The fifth resistance element 35 is a current limiting resistance element.

  The sixth resistance element 36 is connected between the output terminal 48 of the second operational amplifier 38 and the comparison unit 16, one connection terminal is connected to the output terminal 48, and the other connection terminal is connected to the comparison unit 16. The

  The correction circuit unit 39 is realized by a differential VI conversion circuit. The correction circuit unit 39 includes a predetermined voltage Va that is a voltage of the output terminal 45 of the first operational amplifier 37, and a divided voltage Vb obtained by dividing the predetermined voltage Va by the internal resistance element 14 and the external resistance element 13. The current flowing through the sixth resistance element 36 is adjusted according to the difference between the two. The correction circuit unit 39 and the sixth resistance element 36 are provided close to each other. Here, it is sufficient that the correction circuit unit 39 and the sixth resistance element 36 are formed in a collective position in the integrated circuit unit 11, and it is more preferable that they are formed adjacent to each other.

  FIG. 4 is a circuit diagram showing a configuration of the correction circuit unit 39. FIG. 3 also shows the fifth and sixth resistance elements 35 and 36. The correction circuit unit 39 includes pnp bipolar transistors (hereinafter referred to as transistors) Tr1 and Tr2, npn bipolar transistors (hereinafter referred to as transistors) Tr3 to Tr6, and a resistance element 49.

  The bases of the transistors Tr1 and Tr2 are connected to each other. The bases of the transistors Tr3 to Tr5 are connected to each other. The emitters of the transistors Tr1 and Tr2 are both connected to the power supply unit 41. The emitters of the transistors Tr <b> 3 to Tr <b> 5 are all connected to the ground unit 24.

  The collector of the transistor Tr1 is connected to the collector of the transistor Tr4. The collector of the transistor Tr2 is connected to the collector of the transistor Tr6 and to the base of the transistor Tr2. The collector of the transistor Tr3 is connected to the other connection terminal of the sixth resistance element 36. The base of the transistor Tr4 is connected to the collector of the transistor Tr4. The collector of the transistor Tr5 is connected to one connection terminal of the resistance element 49. The base of the transistor Tr6 is connected to the output terminal 45 of the first operational amplifier 37, and the emitter is connected to the other connection terminal of the resistance element 49. The collector of the transistor Tr 7 is connected to the power supply unit 41, the base is connected to one connection terminal of the internal resistance element 14, and the emitter is connected to one connection terminal of the resistance element 49.

In such a correction circuit unit 39, Va is applied to the base of the transistor Tr6 which is the non-inverting input terminal of the differential VI conversion circuit, and is applied to the base of the transistor Tr7 which is the inverting input terminal of the differential VI conversion circuit. Vb, the current flowing through the sixth resistance element 36, the current flowing between the collectors of the transistors Tr1 and Tr4, and the current flowing through the resistance element 49 are I1, and the resistance value of the resistance element 49 is Ra. The resistance value of the sixth resistance element 36 is Rb, the voltage at the connection portion between the output terminal 48 of the second operational amplifier 38 and the sixth resistance element 36 is VT2, and the connection between the fourth resistance element 34 and the collector of the transistor Tr3 is connected. When the voltage of the part, that is, the reference voltage output from the correction circuit unit 39 is VT3, I1 and VT3 are expressed by the following relational expression (2 , Represented by (3).
I = (Va−Vb) / Ra (2)
VT3 = VT2-I1 * R2 = VT2- (Va-Vb) R2 / R1 (3)

  Therefore, if the potential difference between Va and Vb increases, VT3 decreases, and if the potential difference between Va and Vb decreases, VT3 increases. The potential difference between Va and Vb varies according to the resistance value of the internal resistance element 14. If the resistance value of the internal resistance element 14 increases, the potential difference between Va and Vb decreases and the resistance value of the internal resistance element 14 increases. If becomes smaller, the potential difference between Va and Vb becomes larger. In this way, the divided voltage divided by the external resistance element 13 and the internal resistance element 14 changes according to the resistance value of the internal resistance element 14, so that VT3 is changed accordingly, and the comparison unit The reference voltage applied to 16 can be corrected.

  The comparison unit 16 includes a plurality of comparators C. The comparator C compares the voltage generated by the input unit 12 with the voltage generated by the reference voltage generation unit 15 and outputs a comparison result. Each comparator C is provided corresponding to each of the plurality of input units 12, that is, the number of comparators C and the number of input units 12 are selected to be equal. Of the two input terminals included in the comparator, one input terminal is connected to the pull-down resistor element 22 and the input connection terminal 23 of the corresponding input unit 12, and the other input terminal is the other input terminal of the fourth resistor element 34. Connected to the terminal. That is, VT3 is applied to the other input terminal of each comparator C. In the present embodiment, one input terminal is an inverting input terminal and the other input terminal is a non-inverting input terminal. The comparator C outputs a low level signal if the voltage generated by the input unit 12 is larger than the reference voltage, and outputs a high level signal if the voltage generated by the input unit 12 is smaller than the reference voltage. To do.

  As described above, in the comparison circuit device 10 of the present embodiment, in the process of manufacturing the integrated circuit unit 11, the resistance values of the pull-down resistor element 22 and the internal resistor element 14 formed in the integrated circuit unit 11 are Even if the resistance value varies from the resistance value at the design stage, the pull-down resistance element 22 and the internal resistance element 14 are formed close to each other, so that the variation from the resistance value at the design stage becomes almost equal. That is, in the manufacturing process, if the resistance value of the pull-down resistance element 22 becomes lower than the resistance value at the design stage by a predetermined ratio, the resistance value of the internal resistance element 14 also becomes lower than the resistance value at the design stage by a predetermined value. If the resistance value of the element 22 is increased by a predetermined ratio from the resistance value at the design stage, the resistance value of the internal resistance element 14 is also increased by a predetermined ratio from the resistance value at the design stage. The current limiting resistance element 21 and the external resistance element 13, which are external resistance elements provided outside the integrated circuit section 11, have little variation in resistance values.

  Even if the resistance value of the pull-down resistor element 22 varies from the resistance value at the design stage in the manufacturing process of the integrated circuit section 11, the pull-down resistor element 22 and the internal resistor element 14 have the same variation in resistance value. The ratio of the resistance values of the element 22 and the internal resistance element 14 hardly changes. Therefore, by selecting the resistance values of the current limiting resistance element 21, the pull-down resistance element 22, the external resistance element 13 and the internal resistance element 14 so as to satisfy the above-described relational expression (1), The divided voltage obtained by dividing a predetermined voltage by the external resistance element 13 with little variation in resistance value reflects variation in the resistance value of the pull-down resistance element 21. Since the reference voltage generator 15 generates the reference voltage according to the divided voltage, it is possible to generate the reference voltage according to the variation in the resistance value of the pull-down resistor element 22.

  Since the integrated circuit unit 11 is composed of a plurality of chips formed on the wafer at the same time, the resistance value of the pull-down resistor element 22 may vary from chip to chip or from manufacturing lot, and the reference voltage is fixed. Even if the same input signal is given, the comparison result of the comparison unit 16 differs depending on the integrated circuit unit 11, but in this embodiment, the reference voltage generation unit 15 has an internal resistance as described above. Since the reference voltage corresponding to the resistance value of the element is generated, if the same input signal is given, the comparison result of the comparison unit 16 is the same in any integrated circuit unit 11. Therefore, even when the pull-down resistor element 22 is formed in the integrated circuit unit 11, the reliability is high, and compared with the case where the pull-down resistor element is formed outside the integrated circuit unit 11 in each of the plurality of input units 12, The mounting area to be mounted on the circuit board can be reduced, the device can be miniaturized, and the number of resistance elements connected to the outside of the integrated circuit unit 11 can be reduced. The number of processes can be reduced when assembling and mounting on a substrate, and the efficiency of assembly can be improved.

  Further, since the voltage input to the input unit 12 is not measured, but the external resistance element 13, the internal resistance element 14, and the reference voltage generation unit 15 are provided in addition to the input unit 12, the apparatus becomes complicated. There is nothing. Further, even when the resistance value of the pull-down resistor element 22 changes due to a change in temperature such as the outside air temperature, the resistance value of the internal resistor element 14 changes in the same manner as the resistance value of the pull-down resistor element 22. Is adjusted in a timely manner as the resistance value of the pull-down resistance element 22 changes, so that the reliability of the comparison result can be improved.

  FIG. 5 is a circuit diagram showing an electrical configuration of a comparison circuit device 60 according to another embodiment of the present invention. The comparison circuit device 60 of the present embodiment is the same as the comparison circuit device 10 of the embodiment shown in FIG. 3 described above, except that the first and second operational amplifiers 37 and 38 are transistor circuits each combining a transistor and a current source. The other configurations are the same as those of the comparison circuit device 10, and thus the same configurations are denoted by the same reference numerals and redundant description is omitted.

  The transistor circuit 61 includes a pnp bipolar transistor (hereinafter referred to as a transistor) Tr11, an npn bipolar transistor (hereinafter referred to as a transistor) Tr12, and a current source 63.

  A base of the transistor Tr11 is connected to a connection portion between the first resistance element 31 and the second resistance element 32. The emitter of the transistor Tr11 is connected to the current source 63, and the collector is connected to the ground part 24. The current source 63 is connected to the power supply unit 41. The base of the transistor Tr12 is connected to a connection site between the emitter of the transistor Tr11 and the current source 63. The collector of the transistor Tr12 is connected to the power supply unit 41 via the fourth resistance element 34, and the emitter is connected to the connection terminal 26 and the base of the transistor Tr6.

  The transistor circuit 62 includes a pnp bipolar transistor (hereinafter referred to as a transistor) Tr131, an npn bipolar transistor (hereinafter referred to as a transistor) Tr14, and a current source 64.

  A base of the transistor Tr13 is connected to a connection portion between the second resistance element 32 and the third resistance element 33. The emitter of the transistor Tr13 is connected to the current source 64, and the collector is connected to the ground part 24. The current source 64 is connected to the power supply unit 41. The base of the transistor Tr14 is connected to a connection site between the emitter of the transistor Tr13 and the current source 64. The collector of the transistor Tr14 is connected to the power supply unit 41 via the fifth resistance element 35, and the emitter is connected to one connection terminal of the sixth resistance element 36.

  The comparison circuit device 80 of the present embodiment is slightly inferior in accuracy to the comparison circuit device 10, but can achieve substantially the same effect as the comparison circuit device 10 and has a simpler configuration than the comparison circuit device 10. Since the reference voltage can be corrected, the manufacturing process can be simplified and the production efficiency can be improved.

  FIG. 6 is a circuit diagram showing an electrical configuration of a comparison circuit device 80 according to another embodiment of the present invention. The comparison circuit device 80 of the present embodiment is the same as the comparison circuit device 10 of the embodiment shown in FIG. 3 described above, except that the first and second operational amplifiers 37 and 38 are npn bipolar transistors (hereinafter referred to as transistors). This is a configuration in which a reverse connection protection diode (hereinafter referred to as a diode) D is added to each input unit 12 in place of Tr 21 and Tr 22, and the other configurations are the same as those of the comparison circuit device 10. Are denoted by the same reference numerals, and redundant description is omitted.

  The base of the transistor Tr21 is connected to the connection portion of the first resistance element 31 and the second resistance element 32. The collector of the transistor Tr21 is connected to the power supply unit 41 via the fourth resistance element 34, and the emitter is connected to the connection terminal 26 and the base of the transistor Tr6.

  The base of the transistor Tr22 is connected to the connection portion of the second resistance element 32 and the third resistance element 33. The collector of the transistor Tr22 is connected to the power supply unit 41 via the fifth resistance element 35, and the emitter is connected to one connection terminal of the sixth resistance element 36.

The diode D has a cathode connected to the other connection terminal of the current limiting resistance element 21 and an input signal applied to the anode. That is, in this embodiment, the anode of the diode D serves as the input terminal. Diode D and the transistor Tr21,22 is configured, for example, using a silicon, a forward voltage drop of the diode D and Vf, the voltage between the emitter and the base of the transistor Tr21,22 and _{V BE,} and Vf and _{V BE} is Almost equal. In such a configuration, when an input signal is given, a voltage drop is generated by the diode D, and therefore, the voltage generated by the input unit 12 becomes smaller than when the diode D is not inserted. However, the reference voltage generation unit 15 can also reduce the voltage for generating the reference voltage by the diode D by a voltage substantially equal to the voltage drop, and achieve substantially the same effect as the comparison circuit device 10. Since the reference voltage can be corrected with a simpler configuration than that of the comparison circuit device 10, the manufacturing process can be simplified and the production efficiency can be improved.

  FIG. 7 is a circuit diagram showing an electrical configuration of serial interface device 100 according to the embodiment of the present invention. The serial interface device 100 does not have a configuration in which the comparison unit 16 includes a plurality of comparators C in the comparison circuit device 10 of the embodiment illustrated in FIG. 3 described above, but includes one comparator and a semiconductor switch, and a plurality of input units. A comparison / selection circuit 101 that selectively compares a voltage generated by any one of the reference voltages 12 and a voltage generated by the reference voltage generation unit 15; A selection control unit 102 that selectively connects one input terminal of the comparator and any one of the plurality of input units 12 is configured. The selection control unit 102 is realized by a microcomputer. The comparison unit 16 outputs a result of comparing the voltage generated by one input unit 12 among the plurality of input units 12 and the reference voltage.

  According to the present embodiment, it is possible to achieve the same effect as that of the comparison circuit device 10 of the above-described embodiment, and further, it is not necessary to form as many comparators as the number of input units 12, and therefore the circuit of the comparison unit 16 The configuration can be simplified, and a small and highly reliable serial interface device can be realized. The selection control unit 102 may be formed in the integrated circuit unit 11 or may be provided outside the integrated circuit unit 21.

  According to still another embodiment of the present invention, in the above-described comparison circuit devices 60 and 80, the comparison unit 16 is configured by the comparison selection circuit 101 and the selection control unit 102 to configure a serial interface device. May be.

  FIG. 8 is a circuit diagram showing an electrical configuration of a comparison circuit device 110 according to still another embodiment of the present invention. The comparison circuit device 110 according to the present embodiment is the same as the comparison circuit device 10 according to the embodiment shown in FIG. 3 described above, in which the reference voltage generation unit 15 applies a different reference voltage to each comparator C. 111. The other configuration is the same as that of the comparison circuit device 10, and therefore, the same reference numerals are given to the same configuration, and the duplicate description is omitted.

  In the present embodiment, the comparator C having two input units 12 and connected to one input unit 12 is described as a comparator C1, and the comparator C connected to the other input unit 12 is described as a comparator C2. . The comparator C1 is connected to the other connection terminal of the sixth resistance element 36.

  A reference voltage different from the reference voltage applied to the comparator C1 by the reference voltage conversion circuit 111 is applied to the comparator C2. The reference voltage conversion circuit 111 includes an npn bipolar transistor (hereinafter referred to as a transistor) Tr31 and resistance elements 112 and 113. The base of the transistor Tr31 is connected to the other connection terminal of the sixth resistance element 36, the collector is connected to the power supply unit 41, and the emitter is connected to one connection terminal of the resistance element 112. The other connection terminal of the resistance element 112 is connected to the comparator C <b> 2 and one connection terminal of the resistance element 113. The other connection terminal of the resistance element 113 is connected to the ground portion 24. With such a configuration, a reference voltage different from the reference voltage applied to the input terminal of the comparator C1 can be applied to the input terminal of the comparator C2. Therefore, it is possible to achieve the same effect as that of the above-described embodiment, and it can be used for comparing various input signals, and versatility can be improved.

  In still another embodiment of the present invention, the comparison circuit of each embodiment described above is used as an input interface of an electronic device that performs a predetermined process using a result of comparison between a voltage corresponding to a plurality of input signals and a reference voltage. An apparatus may be used, and in this case, the electronic apparatus can be miniaturized.

It is a circuit diagram which shows the structure of the comparison circuit apparatus 1 of a prior art. It is a circuit diagram which shows the structure of the comparison circuit apparatus 7 which provided the resistive element for pulldown outside IC. 1 is a circuit diagram illustrating an electrical configuration of a comparison circuit device 10 according to an embodiment of the present invention. 3 is a circuit diagram showing a configuration of a correction circuit unit 39. FIG. It is a circuit diagram which shows the electric constitution of the comparison circuit device 60 of other embodiment of this invention. It is a circuit diagram which shows the electrical constitution of the comparison circuit apparatus 80 of other embodiment of this invention. It is a circuit diagram which shows the electrical constitution of the serial interface apparatus 100 of one Embodiment of this invention. It is a circuit diagram which shows the electric constitution of the comparison circuit apparatus 110 of further another form of implementation of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10, 60, 80, 110 Comparison circuit apparatus 11 Integrated circuit part 12 Input part 13 External resistance element 14 Internal resistance element 15 Reference voltage generation part 16 Comparison part 17 Reference voltage correction means 21 Current limiting resistance element 22 Pull-down resistance element 23 For input Connection terminal 24 Ground part 25, 26 Connection terminal 31 1st resistance element 32 2nd resistance element 33 3rd resistance element 34 4th resistance element 35 5th resistance element 36 6th resistance element 37 1st operational amplifier 38 2nd operational amplifier 39 Correction circuit section 41 Power supply section 61, 62 Transistor circuit 63, 64 Current source 100 Serial interface device 101 Comparison selection circuit 102 Selection control section 111 Reference voltage conversion circuit

Claims (6)

A comparison circuit device that includes an integrated circuit unit and compares a voltage according to an input signal with a reference voltage,
Each provided with a resistance element for current limiting provided outside the integrated circuit part, and a resistance element for pull-down formed in the integrated circuit part and connected in series with the current limiting resistance element, A plurality of input units for generating a voltage according to the input signal;
An external resistance element provided outside the integrated circuit unit;
An internal resistance element connected in series to the external resistance element and formed in the integrated circuit portion in proximity to the pull-down resistance element;
A reference voltage generation unit that is formed in the integrated circuit unit and generates a reference voltage corresponding to a divided voltage obtained by dividing a predetermined voltage by the internal resistance element and the external resistance element;
A comparison unit that compares the voltage generated by the input unit with the reference voltage generated by the reference voltage generation unit and outputs a comparison result;
When the resistance value of the current limiting resistance element is R1, the resistance value of the pull-down resistance element is R2, the resistance value of the external resistance element is R3, and the resistance value of the internal resistance element is R4, R1, R2, R3 and R4 are
R1: R2 = R3: R4
A comparison circuit device characterized by satisfying The reference voltage generator is
First, second and third resistance elements connected in series between the power supply section and the ground, and for dividing the voltage of the power supply section;
A first operational amplifier in which a non-inverting input terminal is connected to a connection portion of the first resistance element and the second resistance element connected to a power supply section, and an output terminal is connected to the inverting input terminal;
A fourth resistance element connecting the output terminal of the first operational amplifier and the power supply unit;
A second operational amplifier in which an inverted input terminal is connected to a connection portion of the third resistive element connected to the second resistive element and the ground, and an output terminal is connected to the inverted input terminal;
A fifth resistance element connecting the output terminal of the second operational amplifier and the power supply unit;
A sixth resistance element connected between the output terminal of the second operational amplifier and the comparison unit;
A correction circuit unit that corrects a reference voltage by adjusting a current flowing through the sixth resistance element according to a difference between the predetermined voltage at the output terminal of the first operational amplifier and the divided voltage. The comparison circuit device according to claim 1. The reference voltage generator is
First, second and third resistance elements connected in series between the power supply section and the ground, and for dividing the voltage of the power supply section;
A first pnp bipolar transistor having a base connected to a connection portion of the first resistance element and the second resistance element connected to a power supply section, an emitter connected to a current source, and a collector connected to a ground; ,
A first npn bipolar transistor having a base connected to an emitter of the first pnp bipolar transistor;
A fourth resistance element connecting the collector of the first npn-type bipolar transistor and the power supply unit;
A second pnp bipolar transistor having a base connected to a connection portion of the third resistance element connected to the second resistance element and the ground, a collector connected to the current source, and a collector connected to the ground;
A second npn bipolar transistor having a base connected to an emitter of the second pnp bipolar transistor and a power supply connected to a collector;
A fifth resistance element connecting the collector of the second npn-type bipolar transistor and the power supply unit;
A sixth resistance element connected between the emitter and the comparison section of the second npn-type bipolar transistor;
A correction circuit unit that corrects a reference voltage by adjusting a current flowing through the sixth resistance element according to a difference between the predetermined voltage at the output terminal of the first operational amplifier and the divided voltage. The comparison circuit device according to claim 1. Each of the input units includes a diode for reverse connection protection in which a cathode is connected to an end opposite to a side to which a pull-down resistor of a current limiting resistor is connected;
The reference voltage generator is
First, second and third resistance elements connected in series between the power supply section and the ground, and for dividing the voltage of the power supply section;
A first npn-type bipolar transistor having a base connected to a connection portion of the first resistance element and the second resistance element connected to a power supply section;
A fourth resistance element connecting the collector of the first npn-type bipolar transistor and the power supply unit;
A second npn-type bipolar transistor having a base connected to a connection portion of the second resistance element and a third resistance element connected to the ground;
A fifth resistance element connecting the collector of the second npn-type bipolar transistor and the power supply unit;
A sixth resistance element connecting the emitter and the comparison section of the second npn-type bipolar transistor;
A correction circuit unit that corrects a reference voltage by adjusting a current flowing through the fourth resistance element in accordance with a difference between the predetermined voltage at the output terminal of the first operational amplifier and the divided voltage. The comparison circuit device according to claim 1. A serial interface circuit device comprising the comparison circuit device according to claim 1,
The comparison unit selectively compares a voltage generated by any one of a plurality of input units with a voltage generated by a reference voltage generation unit.   An electronic apparatus comprising the comparison circuit device according to claim 1, wherein a predetermined process is performed according to a comparison result of the comparison unit.

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