JP3533842B2 - Constant voltage circuit - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a constant voltage circuit.

[0002]

2. Description of the Related Art A conventional constant voltage circuit will be described with reference to FIGS. FIG. 1 is a diagram showing a constant voltage circuit. FIG. 2 is a layout plan view showing an example of the arrangement position of each block corresponding to the circuit diagram of FIG. FIG. 7 shows the resistive element group 207 and the resistive element group 21 shown in FIG.
7 is a conventional layout plan view showing further detailed arrangement positions of FIG.

The first amplifying means 102 has an output voltage VOUT1.
Is divided by the A1 resistance element 108 and the A2 resistance element 109,
Since feedback is applied to the differential amplifier circuit 103, it functions as a constant voltage circuit. Therefore, the output voltage VOUT1 is A1
When the resistance value of the resistance element 108 is R A2 and the resistance value of the A2 resistance element 109 is R A1

[0004]

[Equation 1]

It is represented by

Since the second amplifying means 112 also has the same configuration as the first amplifying means 102, it also functions as a constant voltage circuit, and the output voltage VOUT2 has the resistance values of the B1 resistance element 118 as R B2 and B2 resistance element 119. Let the resistance value of R B1 be

[0007]

[Equation 2]

It is represented by

[0009]

However, in the conventional constant voltage circuit described above, as shown in FIG. 7, the first resistance element 708 (hereinafter referred to as A1 resistance element) belonging to the first amplification means is used. Second resistance element 709 belonging to the first amplifying means (hereinafter referred to as A2 resistance element) and the first resistance element 718 belonging to the second amplifying means (hereinafter referred to as B).
1 resistance element), and the second belonging to the second amplification means
Since the arrangement position of the resistance element 719 (hereinafter referred to as the B2 resistance element) is composed of one resistance element, respectively, due to manufacturing variations between wafers or lots,
Since the resistance value of each resistance element varies and the current flowing through the resistance element also varies, the current consumption of the entire constant voltage circuit also varies, so increase the battery capacity especially in the power design of small portable devices that require low power consumption. There is a first problem that it is necessary to design in consideration of an equal margin. That is, the resistance variation due to the manufacturing variation between the wafers or lots of the resistance values RA1, RA2, RB1, and RB2 is Δ.
If RA1, ΔRA2, ΔRB1, and ΔRB2, the resistance element group 70
8 and 709, the current IOUT1 flowing through the resistor element group 71
The current IOUT2 flowing through 8,719 is

[0010]

[Equation 3]

[0011]

[Equation 4]

The value of the current flowing through the resistance element varies.

Also, A1 resistance element 708, A2 resistance element 709, B1 resistance element 718, and B2 resistance element 719.
Have a second problem that the resistance value varies due to manufacturing variations inside the chip. That is, the resistance values RA1, RA2, RB1, R
Resistance variation due to manufacturing variation of B2 is δRA
1, δRA2, δRB1, δRB2, the output voltage VOUT
1, VOUT2

[0014]

[Equation 5]

[0015]

[Equation 6]

The voltage value varies between the output voltages VOUT1 and VOUT2. Therefore, in order to obtain the desired characteristics, it is necessary to provide a terminal, a fuse circuit, or the like for each constant voltage circuit in order to adjust the output voltage value, which increases the chip area.

Therefore, the present invention solves such a problem, and an object of the present invention is to reduce variations in current consumption of a constant voltage circuit between wafers or lots due to variations in manufacturing between wafers or lots. There is a place to hold down. A further object of the present invention is to provide a constant voltage circuit in which the relative value of the output voltage between the constant voltage circuits is constant, without depending on manufacturing variations inside the chip.

[0018]

[0019]

[0020]

The invention according to claim 1 is
It comprises a reference voltage generating means, a first amplifying means and a second amplifying means which receive the reference voltage generated by the reference voltage generating means as an input and output a real multiple of the voltage value of the reference voltage. The amplifying means includes a differential amplifying circuit, an output amplifying circuit that receives an output signal of the differential amplifying circuit, and a capacitive element provided between the output of the differential amplifying circuit and the output amplifying circuit. The output amplifier circuit includes an active element that receives an output signal of the differential amplifier circuit as an input signal, the first resistance element and a second resistance element that are connected in series with the active element, and the first resistance element and the second resistance element. In a constant voltage circuit in which a connection point between the resistance element and the second resistance element is negatively fed back to the differential amplifier circuit, the first resistance element and the second resistance element of each amplification unit are At least two or more in each of the first direction and the first direction in the first direction. The first resistance element belonging to the amplifying means and the first resistance element belonging to the second amplifying means are alternately arranged, and the second resistance element belonging to the first amplifying means and the second resistance element belonging to the second amplifying means. The second resistance elements belonging to the amplification means are alternately arranged.

The invention according to claim 2 is the constant voltage circuit according to claim 1 , wherein the first resistance element and the second resistance element are provided.
The resistance element is divided into at least two or more elements in a second direction substantially orthogonal to the first direction.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. The invention according to claim 1 will be described with reference to FIGS. 1, 2, and 3. FIG. 1 is a circuit diagram showing a constant voltage circuit when there are two amplifying means. The reference voltage generating means 101 supplies the reference voltage VREF to the first amplifying means 102 and the second amplifying means 112.

The first amplifying means 102 is the operational amplifier circuit 1
03, an output amplifier circuit 104, and a capacitive element 105 for phase compensation. The output amplifier circuit 104 is Pc
It is composed of an h transistor 106 and a resistance element group 107, and the resistance element group 107 further includes an A1 resistance element 108.
And an A2 resistance element 109.

The second amplifying means 112 is the operation amplifying circuit 1
13, an output amplifier circuit 114, and a capacitive element 115 for phase compensation. The output amplifier circuit 114 is Pc
The h-transistor 116 and the resistance element group 117 are included, and the resistance element group 117 includes the B1 resistance element 118.
And a B2 resistance element 119.

FIG. 2 is a layout plan view showing an embodiment of the location of each block corresponding to the circuit diagram of FIG. Reference numeral 201 in FIG. 2 denotes the reference voltage generating means 101 in FIG.
It corresponds to. Similarly, the other blocks correspond to those in FIG. 1, in which 202 is the first amplification means 102, 212 is the second amplification means 112, and 203 and 213 are the operation amplification circuits 103.
And 113, 204 and 214 are output amplifier circuits 104 and 11
4, 205 and 215 are capacitive elements 105, 115 and 206.
And 216 are Pch transistors 106, 116 and 207.
And 217 correspond to the resistance element groups 107 and 117, respectively.

FIG. 3 is a diagram showing the location of the resistive element. Reference numeral 307 denotes a resistance element group, which corresponds to the resistance element groups 107 and 117 in FIG. 1 and the resistance element group 20 in FIG.
It corresponds to 7 and 217. Reference numeral 308 corresponds to the A1 resistance element 108 in FIG. 1, and hereinafter 309 corresponds to the A2 resistance element 109, 318 corresponds to the B1 resistance element 118, and 319 corresponds to the B2 resistance element 119, respectively. Reference numeral 321 represents a first wiring means, 323 represents a contact electrically connecting the resistance element and the first wiring means 321.

Further, FIG. 3 shows A in the first direction in FIG.
1 resistance element 708, B1 resistance element 718 divided into four, A2
In this embodiment, the resistance element 709 and the B2 resistance element 719 are divided into eight.

In general, when a sample of random numbers n is randomly sampled from a population that has a normal distribution with an average value μ and a standard deviation σ, the distribution of the average values of the samples is also a normal distribution, and the average value μ and the standard deviation σ are / √n.

Therefore, since the variation between lots or wafers varies in a normal distribution, when each resistance element is divided into n, the standard deviation of the average value of the resistance elements becomes 1 / √n, and the variation is suppressed. For example, if each resistance element is divided into n, the current IOUT3 flowing through the resistance elements 308 and 309
1 and the current IOUT32 flowing through the resistance elements 318 and 319
Is the resistance fluctuations ΔRA1 and ΔRB1 in the equations (3) and (4).
1 / √n1 and resistance fluctuations ΔRA2 and ΔRB2 are respectively multiplied by 1 / √n2 to obtain the following equation.

[0030]

[Equation 7]

[0031]

[Equation 8]

Therefore, in the embodiment shown in FIG. 3, the A1 resistance element 308 and the B1 resistance element 318 are 1 / √4 = 0.
5, A2 resistance element 309 and B2 resistance element 319 are 1 / √
The variation can be suppressed by 8≈0.35.

Next, the invention described in claim 2 will be described with reference to FIGS.
And FIG. 4 will be described. 1 and 2 have already been described.

FIG. 4 is a diagram showing the location of the resistance element. Reference numeral 407 denotes a resistance element group, which corresponds to the resistance element groups 107 and 117 in FIG. 1 and the resistance element group 20 in FIG.
It corresponds to 7 and 217. Reference numeral 408 corresponds to the A1 resistance element 108 in FIG. 1, and similarly 409 corresponds to the A2 resistance elements 109, 418 to the B1 resistance elements 118 and 419 to the B2 resistance element 119, respectively. 421 is a first wiring means, 423 is a contact electrically connecting the resistance element and the first wiring means 421.

FIG. 4 shows the A1 resistance element 308 in FIG.
This is an example in which the A2 resistance element 309, the B1 resistance element 318, and the B2 resistance element 319 are each further divided into two in the second direction. The second direction is a direction different from the first direction and is, for example, substantially orthogonal to each other. Therefore, compared with the conventional example, as a result, A1 resistance elements 408, B1
The resistance element 418 is divided into eight parts, and the A2 resistance element 409 and the B2 resistance element 419 are divided into sixteen parts, so that the variation in the resistance value can be further suppressed.

Next, the invention described in claim 3 will be described with reference to FIGS.
And FIG. 5 will be described. 1 and 2 have already been described.

FIG. 5 is a diagram showing the location of the resistive element. Reference numeral 507 denotes a resistance element group, which corresponds to the resistance element groups 107 and 117 in FIG. 1 and the resistance element group 20 in FIG.
It corresponds to 7 and 217. Reference numeral 508 corresponds to the A1 resistance element 108 in FIG. 1, and hereinafter 509 corresponds to the A2 resistance elements 109, 518, B1 resistance elements 118 and 519, respectively. 521 is a first wiring means, 522 is a second wiring means, 523 is a contact for electrically connecting the resistance element and the first wiring means 521, 523 is an electrical connection between the wiring means 521 and the wiring means 522. Represents a connected through hole.

Further, FIG. 5 shows the A1 resistance element 50 in the first direction.
8 and B1 resistance element 518 are divided into two, and A2 resistance element 50
9 and B2 resistance element 519 are divided into four, and further, A1 resistance element 508, B1 resistance element 518, and A2 resistance element 5
In this embodiment, 09 and B2 resistance elements 519 are alternately arranged.

The effect of the division is as described in the embodiments of claims 1 and 2.

As shown in FIG. 5, A1 resistance elements 508 and B1
Since the resistance element 518 and the A2 resistance element 509 and the B2 resistance element 519 are arranged alternately,

[0041]

[Equation 9]

Therefore, the equation (9) is substituted into the equations (5) and (6) to obtain the following equation.

[0043]

[Equation 10]

[0044]

[Equation 11]

For example, when the resistance values of the resistance element groups are equal, that is,

[0046]

[Equation 12]

Then, the output voltages VOUT1 and VOUT2 are obtained by substituting the equation (9) into the equations (10) and (11).

[0048]

[Equation 13]

The resistance variation due to manufacturing variations is canceled out, and the output voltages VOUT1 and VOUT2 become equal. Also in the case of a constant voltage circuit that outputs different voltages for the output voltages VOUT1 and VOUT2, the resistance variation is canceled out in the same manner, and the relative value of each output voltage becomes constant.

Next, the invention described in claim 4 will be described with reference to FIGS.
And FIG. 6 will be described. 1 and 2 have already been described.

FIG. 6 is a diagram showing the location of the resistive element. Reference numeral 607 denotes a resistance element group, which corresponds to the resistance element groups 107 and 117 in FIG. 1 and the resistance element group 20 in FIG.
It corresponds to 7 and 217. Reference numeral 608 corresponds to the A1 resistance element 108 in FIG. 1, and hereinafter 609 corresponds to the A2 resistance element 109, 618 corresponds to the B1 resistance element 118, and 619 corresponds to the B2 resistance element 119, respectively. 621 is a first wiring means, 622 is a second wiring means, and 623 is a contact which electrically connects the resistance element and the first wiring means 621.

FIG. 6 shows the A1 resistance element 508 in FIG.
This is an example in which the A2 resistance element 509, the B1 resistance element 518, and the B2 resistance element 519 are each further divided into two in the second direction. The second direction is different from the first direction and is, for example, substantially orthogonal. Therefore, compared with FIG. 5 shown in the embodiment of claim 3, the variation can be further suppressed to about 0.71.

FIG. 8 is a sectional view when the resistance element is a polysilicon resistance. 821 is a first wiring means, 822 is a second wiring means, 823 is a contact through hole, 82
Reference numeral 4 is a through hole, 825 is polysilicon serving as the resistance element, 826 is an interlayer insulating film, and 827 is a substrate. Other resistance elements include well resistance,
Diffusion resistance, MOS resistance, polysilicon diode resistance, etc. can be considered.

[0054]

As described above, according to the present invention, by dividing the resistance element, the variation in the current consumption of the constant voltage circuit between the wafers or lots is caused by the variation in the manufacturing between wafers or lots. Since the power consumption can be suppressed, it is not necessary to consider an unnecessary power margin at the design stage of a small portable device that requires low power consumption, and the capacity of a battery to be mounted can be reduced.

Further, according to the present invention, by arranging the resistance elements alternately, a constant voltage circuit in which the relative value of the output voltage between the constant voltage circuits is constant is provided even if manufacturing variations exist in the chip. Therefore, a set of terminals for adjusting the output voltage value, a fuse circuit, and the like can be provided, and an increase in the chip area can be prevented.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a constant voltage circuit.

FIG. 2 is a layout plan view showing an example of an arrangement position of each block corresponding to the circuit diagram of FIG.

FIG. 3 is a layout plan view of a resistance element group showing an embodiment of the invention described in claim 1;

FIG. 4 is a layout plan view of a group of resistance elements showing an embodiment of the invention described in claim 2;

FIG. 5 is a layout plan view of a group of resistance elements showing an embodiment of the invention described in claim 3;

FIG. 6 is a layout plan view of a group of resistance elements showing an embodiment of the invention described in claim 4;

FIG. 7 is a layout plan view of a resistance element group showing a conventional example.

FIG. 8 is a cross-sectional view when the resistance element is polysilicon.

[Explanation of symbols]

101, 201 ... Reference voltage generating means 102, 202 ... First amplifying means 112, 212 ... Second amplifying means 103, 113, 203, 213 ... Differential amplifying circuits 104, 114, 204, 214 ... Output amplifier circuits 105, 115 205, 215 ... Capacitance elements 106, 116, 206, 216 ... Pch transistors 107, 117, 207, 217, 307, 407, 5
07, 607, 707 ... Resistance element groups 108, 308, 408, 508, 608, 708 ...
First resistance elements 109, 309, 409, 509, 609, 709 belonging to the first amplification means
The second resistance elements 118, 318, 418, 518, 618, 718 belonging to the first amplification means
First resistance element 119, 319, 419, 519, 619, 719 belonging to the second amplification means
-Second resistance elements 321, 421, 521, 621, 721, 821 belonging to the second amplification means.
First wiring means 322, 522, 822 ... Second wiring means 323, 423, 523, 623, 723, 823 ...
Contact 324, 524, 824 ... Through hole 825 ... Polysilicon resistance 826 ... Interlayer insulating film 827 ... Substrate

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) G05F 1/00-1/70 H01L 27/04 H03F 3/45

Claims (2)

(57) [Claims] 1. A reference voltage generating means, and a reference voltage generated by the reference voltage generating means as an input,
It is composed of first amplifying means and second amplifying means for outputting a real multiple of the voltage value of the reference voltage, and each amplifying means receives a differential amplifying circuit and an output signal of the differential amplifying circuit. And an output element of the differential amplifier circuit and a capacitive element provided between the output amplifier circuit, the active element receiving the output signal of the differential amplifier circuit as an input signal. And a first resistance element and a second resistance element connected in series with the active element, and connecting the connection point of the first resistance element and the second resistance element to the differential amplifier circuit. In the negative feedback constant voltage circuit, each of the first resistance element and the second resistance element of each amplification means is divided into at least two or more in the first direction, and the first resistance element and the second resistance element are divided into at least two in the first direction. The first resistance element belonging to one amplification means and the first resistance element belonging to the second amplification means. Constant voltage, wherein the second resistance elements belonging to the first amplifying means and the second resistance elements belonging to the second amplifying means are arranged alternately. circuit. 2. The constant voltage circuit according to claim 1, wherein the first resistance element and the second resistance element are the first resistance element and the second resistance element.
The constant voltage circuit is characterized by being divided into at least two or more parts in a second direction substantially orthogonal to the direction of.