JPS603012A - Reference voltage generator - Google Patents

Abstract

PURPOSE:To set the temperature coefficient of an output to zero by providing a reference voltage generator with a voltage generator which generates a voltage in logarithmic proportion to absolute temperature, and supplying the output of the reference voltage generator to an adder together with the output of a voltage generator which is proportional to the absolute temperature. CONSTITUTION:A current source 11 supplies a current proportional to the power of the absolute temperature to the collector of a transistor (TR)12. The output VBE of this TR12 is supplied to an adding circuit 13. This adding circuit 13 is supplied with the output voltages of the voltage generator 14 which generates the voltage proportional to the absolute temperature and the generator 16 which generates the voltage proportional to the logarithm of the absolute temperature. Those three voltages are summed up, and the sum voltage VON appears at an output terminal 15. Then, coefficients E and D which are determined by constants obtained previously from semiconductor formation conditions are used to constitute a circuit, so that an invariably constant voltage is generated regardless of temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a pressure generator suitable for integrated circuits.

[Technical Background of the Invention and Intervals] Conventionally, a reference voltage generator called a bandgap reference has been frequently used in integrated circuits.

Figure 1 shows the basic configuration of such a conventional pressure generator, where 1 is π [corrosion], 2 is a diode-connected transistor, 3 is an additive, and 4 is an absolute temperature It is a generator of voltage proportional to , and the output generated at the collector of transistor 2 and 1! ! , pressure';C; and the output of the generator 4 are energized by the energizer 3) and guided to the output end f5. In such a reference voltage generator, the relationship between the collector current IC of the transistor 2 and the base-emitter voltage VBII is given by the following equation.

#VnE Here, Is is a saturation current, fF is an electron charge, is Boltzmann's constant, and T is an absolute value of 7.171 degrees.

In fact, it is known that the saturation button 1s is 1s. Here, Iso is a saturation current constant, p is a constant, and ■G is a forbidden charge voltage of a semiconductor constituting a transistor, which has a constant value.

(1) When formula fc is transformed, becomes. Substituting equation (2) into this, we get:

On the other hand, the output voltage Vo generated at the output terminal 5 is given by. Here C is a constant. Therefore, by substituting the above equation (4) into this equation (5), the following equation holds true.

T Vo = Vo + − [1nIc-dnIso-P/
+n'r+C:] -(6)? In equation (6), by appropriately selecting C, the temperature coefficient of the output voltage Vo can be set to O at a certain temperature. However, in reality, as is clear from equation (6), no matter how the value of C is selected, it is not possible to make the output 117 and the temperature coefficient of pressure 0 over a wide temperature range.

FIG. 2 shows the temperature characteristics of a conventional reference voltage generator, which always changes with temperature.

[Purpose of the invention]

An object of the present invention is to improve the drawbacks of conventional reference voltage generators and to provide a reference voltage generator whose output voltage is constant regardless of temperature.

[Summary of the invention]

This invention further provides a voltage generator that generates a pressure 'ii' proportional to the logarithm of absolute temperature to the conventional obsolete reference voltage and pressure generator shown in FIG. 'iii, together with the blade of the pressure generator, it is fed to the adder circuit and added to the liquid between the base and emitter of the transistor with U1 constant Q EQ, thereby increasing the temperature coefficient of output 1
1114'<0.

[Embodiments of the invention]

The book 41 will be explained in detail below with reference to the light turn l i/+'i.

The 31st column 1 shows the basic structure of the 31st column reference voltage generator. 1, 1 is a current source, which supplies the collector of the transistor 12 with a voltage 11 (11) (·, ?tC) relative to the power of the absolute temperature. The emitter of the transistor 12 is grounded, and the base This is a transistor connected to a diode J, whose collector is commonly grounded.The voltage VBE between the base and emitter of this transistor 12 is supplied to the adding circuit 13. The fj circuit 13 is supplied with an output i' from a voltage generator 111 which generates a voltage proportional to the absolute temperature, a pressure generator 14, and a generator 16 which generates a voltage f proportional to the absolute temperature. These three voltages are then added together, and the added voltage VON is the output terminal 15.
can be obtained.

Next, the I! of this standard 1b4 pressure generator! ''j Sakuhara, pl
j fExplain.

In the reference box pressure generator according to the present invention, J′: the output 1 pressure V
ON is 2'11. Here, J), E are constants, 'Vr I'
I'm suitable ■.

It's pressure. Substituting this equation (7)2K(4), assuming that the temperature characteristics of the collector current Ic are Ic=G, TQlo, (91), equation (8) can be reduced to 1 as follows.

becomes. Here, if it is 1 Lee P-Q, the output name and pressure VON will be Va, which will be 15jp', 11°2, regardless of the temperature.

Here, the constants J P and Iso can be determined legally based on the transistor manufacturing conditions, and it is easy to determine the constants J P and Iso. 314 per cent '1 [5 voltage Vr is equal to output voltage VON! I can do it.

In this way, according to Furuaki, the circuit is constructed using coefficients E and D determined in advance from constants determined from the conditions of the semiconductor idle time, and the circuit is always set at one series regardless of the temperature. ．． Can generate pressure.

Figure 4 shows a typical example of Book-81 (Ming). This example shows two peaks with different dependencies on the absolute crystallinity,
A current source 11, l8, two transistors 12,19 respectively connected to them, a voltage generator 14 generating a pressure proportional to the absolute vortex layer, and a
! , Nuki 13 is yelling.

11L flow thp 1 ]-, 1a Koma, flow value Ici,
It is assumed that the temperature characteristics of Ic2 can be expressed by the following equations.

I c 1-Gi T"" - (13)' o2 Ic2 = G2T- (14) At this time, the base-emitter voltage VnE1 of the transistor 12.19. VnF, 2td, (4'1 formula, l:"
), it will look like this:

kT VB E 1 =: −(6nGl+Q1 ln]+−
, :low SO1-J)7n'j) +1h3 ,,
, (I history( kTVs E 2 = −(lnG2+Q21nT−11n
I s O2-P7n'I) -1-V(i -06
) where l5o3 and l5o2 are the saturation current constants of the transistors 12 and 19, respectively. '11 pressure 7
Illτ-1 partner: ÷13 kT VBEI, VBE2. −, the addition coefficient for (
1+k), (-k), F, output 'Y14, pressure V
ON is given by the following equation.

Substituting equation (15) (Qg) into this equation, kT VoN = -(, dnGl-g, 117nT-7nI
sot-P7nT) +VGokT QI GI l5o2 -■vomit 1C4-give up chest/rejection/■-10F] 1(T ←(K (Ql -42) +Q1-PMnT -(1
8)? That's it. Here, regarding the addition coefficient of the voltage adder, l5
OI K+I G2 K 1゛゛-nonnC (te1 ``Is revised)〕 ... (20
), the output voltage VON becomes a constant voltage VG regardless of the temperature.

In this embodiment, the third term in equation (7), which is proportional to the absolute temperature T, is replaced by two current sources with different characteristics: +g< IfJt It is characterized by being generated from a voltage difference of t41 pressure.

In this embodiment, the voltage proportional to the absolute temperature is generated by a known circuit that takes advantage of the fact that the voltage difference between the base-emitter voltages of two transistors with a constant L current ratio is proportional to the absolute temperature. 'I can live. It's great, (j3) formula (
14) In order to create a flow, the temperature dependence as shown in equation
For example, the above absolute t is equal to 4.
l'l' Fli, k can be easily realized by applying it to a resistance whose temperature dependence is proportional to the power of the absolute temperature.

FIG. 5 shows another practical example of the present invention.

In this embodiment, the 2111th current source 18 in the previous embodiment (() is replaced with a voltage-current converter 20 that generates a 7"C6 current in proportion to the output power FEE. In this case (
Either G2 in equation 14) becomes 0, or equation (18) is created as is, and as described above, the output 'iN becomes a constant value -G regardless of the compression temperature. The motivation for the storage example is the output, etc.
From temperature k(constant +4+, 'pressure to constant frost, regardless of age, flow to Klr).

FIG. 6 shows another embodiment of the invention. In this embodiment, the transistors 21 and 2241 have resistors 26 and 27°28.2.
9 and an operational amplifier 35, a box 1 voltage adder consisting of a resistor 30.31 and an operational amplifier 36, a transistor 23, a resistor 32, 33, 34 and an operational amplifier Another device 5 consists of a pressure generator 37 and a pressure generator. First, the output box pressure for the two πj pressures is determined, and then the overall operation will be explained.

Calculate the output voltage of the 1-pressure generator for sweets.

The collector currents of transistors 21 and 22 are respectively Ic
1, Ic2, and the resistance values of resistors 2fi and 27 are I(, 26, R, 27, respectively. For simplicity, assume that the saturation % I of transistor 21 and 22 is clear, and the current is clear.
The voltage Δvbe developed across the resistor 28 is. Performance 9
Resistor 26 and resistor 270 for the negative feedback effect of amplifier 35
Since the air and pressure at both ends are equal, Icl i726 =
Ic2 几27 ...(22) holds true. Therefore, equation (21) becomes as follows.

Assuming that the current amplification factors of the transistors 21 and 22 are sufficiently large, the current Δvbe/R28 flowing through the resistor 28 is approximately equal to IC1. In other words, it is. Here, R8 is the resistance value of the resistor 28.

Moreover, using equation (22), it is as follows. Since the current flowing through the resistor 29 is the sum of IC1 and IC2, the frost and voltage V29 generated across the resistor 290 are as follows. Here, R129 is the resistance value of the resistor 29.

If defined, TV29=A・−・(28) ? I can stay with you. Pace emitter 114 of transistor 22
1? When the lXi pressure is VBE22, the output 1:·pressure VOI at 190 points is given by the following equation.

T Vo+ = VBE22 +A-... (29) Saturation of the detransistor 22 11) If the current constant is lSO2, then from equation (4), T VBE22 = -(lnIc2-lnIso2-Pl
nT) +VG -(30)? It is. IC2 is given by equation (16) and is proportional to the absolute temperature T, so if the proportionality coefficient is G, then IC2= (
i T −(31), where. If the above is set to 1, equation (29) becomes the following equation.

T VOI = VG-1--(ln(3T-lnIso2
-PlnT4-A) -(33)? Next, calculate the output 'i1f pressure of another I1 pressure generator. Resistance values of 32, 33, and 340 are R32 and R, respectively.
33, R, 34. The output voltage of this entire device is 41
As will be described later, since the value is VG, the collector air flowing through the transistor 3 is the first-class IC3.
is expressed by the following equation, and is constant regardless of temperature if the temperature coefficient of resistance is negligibly small.

Therefore, the output box voltage VO2 at the 20 points is the voltage between the base and emitter of the transistor 23 such that a"i-L<
, if the saturation tFL current constant of transistor 3 is lSO3, then from equation (4), 11 VO2=Va+-(lnIc3-7nIso3-Pln
T) −=(35)? It is.

The resistance values of resistors 30 and 31 are each 1% 30.

Assuming R31 and its resistance ratio, the voltage adder will produce the voltage ■01 that appears at point 39.
By inputting the voltage VOZ appearing at the point 40, the output voltage Vo3 of the entire device is generated as expressed by the following equation.

VO3=Vot1K (VOI-VO2)...(3
7) For simplicity I s o 2 = I s o 3
= I s o , the above equation is expanded as follows.

T Vo 3 = Va+-(A! n(Jr-71n I
s o-Pl n'1. "+A)? T 0-(ly+1lnG'I'-1n I c 3)T -1-(K+1-P)lnT...(38)Z・ Therefore, VCl can be converted by equation (27) and equation (36). By adjusting the circuit constants A and K as shown in equations (39) and (40), the output voltage VO3 can be set to a constant value Vo regardless of the temperature.

K2P-1...(39) FIG. 7 shows another embodiment of the present invention.

As in the previous embodiment, the first "jL1 pressures given by equations (33) and (35) are generated at points 39 and 40, respectively. Therefore, the resistor 30 has a current given by the following equations. 11 o flows.

Ilo = -(Vot -V'02)...(41)
R3゜Base 1 of transistor 21 and transistor 22 (j1
If the current is negligibly small compared to this current, a current approximately equal to this current will flow through the resistor 31, so the point 4
Output 1: 1.1. 'tE Vo31d-
It is given by the same formula as formula 1 (38). The characteristic of 0 cases is that there is one 'voltage generator' and 'tI'8. The point is that it also has the function of pressurizing 31.

FIG. 8 shows an example in which a transistor is used in place of the arithmetic multiplier shown in FIG. 7.

Transistors 54, 55, 56, 57, 58°59 and constant current sources 82 and 83 constitute an operational multiplier, and resistors 70,
7],,72,73. ) Together with transistors 21 and 22, a voltage V01 given by equation (33) is generated at point 87. Transistors 61, 62, 63, 64, 65, 6
6 and constant current source 84゜85 is another performance increase 11''ν
J is 1"4, and along with resistors 79, 80, 81, and transistor 60, there is a circuit that can be connected to point 88 according to equation (35),
Generates pressure Vo2.

The output 11te pressure V03 of the entire device is at point 89,
As in the previous embodiment, it is given by equation (38).

Resistor 75 and transistors 67, 68, and 69 determine the base potential of transistor 53. The base-emitter voltage of transistor 67 is the same as that of transistor 59.
Since the pressure between the base and emitter of transistors 67 and 68 is approximately equal to π°C pressure, the current of V
o 3 (=VG) and the resistor 74 set the temperature 16-
It remains almost constant regardless of the (However, transistor 67
．． It is assumed that the stop current expansion rate of No. 68 is sufficiently high. ) Since the base-emitter voltages of transistors 68 and 69 are the same, a current determined by the saturation current of transistors 18 and 19 flows through resistor 75. One end of the resistor 75 is connected to a point 89, and its potential is Vo 3 (=Vo). Therefore, a substantially constant voltage is generated at the base of transistor 530 regardless of temperature, which is determined by the ratio of resistors 74 and 75 and the saturation 1F of transistors 68 and 69.

The value of the resistor 70.71 and the saturation of the transistor 53 to the transistor 52 are expressed as
By setting □+li'-, transistors 51 and 5
The temperature dependence of the potential of the collector 2 can be arbitrarily determined as i'.

For example, by setting the collector potentials of transistors 51 and 52 to be approximately equal to the base voltage over a wide temperature range, the voltage of the Erthor effect of transistors 51 and 52 is
It is possible to significantly reduce the impact on I.

In addition, by setting the first emitter of the transistors 54 and 55 to a high potential, the current source 8 can be
It is also possible to prevent the saturation phenomenon of the transistors constituting 2.

If the q-first market increase rate of transistor 54.54 is low,
Due to the influence of the current at the base of the transistor 54.55,
The collector current ratio of transistors 5], , 52 deviates from the value determined by the ratio of resistor 70.71, and therefore Vo
+ klX difference occurs. The saturation current ratio of transistor 56.57 is the collector BE 1 of transistor 51.52.
This can be prevented by making the lrf ratio inferior. In general, 1<':n', the matching of flow amplification factors between adjacent transistors in the circuit is very good, so the pace current ratio of transistors 54.55 is is equal, and in this case it is also equal to the collector 1:j current of the transistor 51.52. At this time, by setting the saturation current ratio of the transistor 54.55 to be equal to the collector current ratio of the transistors 5], , , 52, the difference between the base 1 and 7 of the transistor 54.55 is reduced by the transistor 51.52. collector current ratio of 4. This can be avoided by minimizing the north determination error.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to provide a reference voltage generator that can generate a constant level of frost 1 pressure f irrespective of changes in degree.

[Brief explanation of the drawing]

Figure 1 is an original diagram of a conventional reference voltage generator, and Figure 2 is:
The temperature diagram of the conventional reference voltage and pressure generator, Figure 3, is as follows:
The operating principle diagrams of the present invention, FIGS. 4 to 8, are diagrams 41 showing embodiments of the present invention. 11... Current source, 12... Transistor, 13...
・Frost pressure adder, 14... Generator of temperature proportional to absolute temperature, 15... Output section. Pressure, 16...group 1. A generator of 1M1 pressure proportional to 11 lines and 1 line. Agent Patent attorney Nori Satsuki Chika (and 1 other person)＼ □shi, Q Return to Figure 4 Figure 5

Claims (3)

[Claims] (1) A lightning voltage generator that generates a small voltage proportional to the absolute temperature, and a lightning generator that generates a voltage proportional to the logarithm of the absolute temperature.
a pressure generator, a current generator that generates a current proportional to the power of absolute temperature, a transistor connected to this current generator, and a base-emitter voltage of this transistor.
voltage and the output voltage f of the two voltage generators;
7. A reference voltage generator comprising: a pressure-delivery needle; and a reference voltage generator. (2) The voltage proportional to the logarithm of the absolute temperature is expressed as a power of the absolute temperature r, 13 points 1! 2":) 'l^; which generates currents with different characteristics, and Fj+I 1., y'c are obtained by the base-emitter of two transistors I!4jliI pressure Δ- Claim 3 characterized in that: 1λ enclosing first
4.2 (Reference voltage generator). (3) One of the two flow generators generates the number of peaks with the hot water temperature characteristic in the form of a power of the absolute humidity. The reference voltage generator according to claim 2, wherein Il and 'Ifa are those for converting into a current proportional to the reference voltage generator.