JPH03160513A - Reference voltage generating circuit made into semiconductor integrated circuit - Google Patents

Abstract

PURPOSE:To suppress the absolute value dispersion of a reference voltage to be small by subtracting the current of a current generating circuit where positive temperature coefficient is large from the current of a current generating circuit where positive temperature coefficient is small and impressing a subtracted result to a reference resistor. CONSTITUTION:When resistors R2 and R1 for current set are set to be R1>R2 so as to obtain I2>I1, the temperature change of constant current sources Io2 and Io1 can obtain a characteristic with the large I1 and the small I2 for an absolute value. For the I2, the same current as the I2 is outputted from the collector of a transistor Q6 by a current mirror circuit composed of transistors Q5 and Q6, and the I2 is connected serially to the collector output I1 of the transistor Q5. Then, the current of I3=I2-I1 is outputted. In such a case, the generated current I3 with a negative temperature coefficient is added and synthesized with the current I0 of a constant current source equipped with a voltage JBE difference between the base and emitter of transistors Qo1 and Qo and the positive temperature coefficient to be set by a resistor Ro. Then, the result is impressed to a reference resistor Rref. Thus, the temperature coefficient of the reference voltage can be set to 0.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention is intended for use in electronic circuits (semiconductor integrated circuits (hereinafter referred to as ICs)) that are stable and stable against temperature fluctuations, power supply fluctuations, etc. This relates to the circuit structure of a reference DC voltage generation circuit with a small amount of noise, and can be widely applied to camera strobe control circuits, control equipment circuits, etc. [Conventional technology] Figure 3 shows a conventional reference voltage generation circuit. FIG. In the figure, (Dref) is a reference diode, (Ion) is a current source, (Qo), (Q,or) are bipolar transistors, (Ro) is a resistor, and (Rref) is a reference resistor. The bases of Q, o+) and (Qn) are commonly connected, and the base and erector of the transistor (Qot) are short-circuited to form a diode structure.
It is connected in series with a current source (Ion) and connected to a power supply Vcc. Also, the emitter of Towonjinuta (Qo.> is GN)
It is connected to the O (earth) line, and the transistors (Q,
The emitter of o) is connected to a resistor (R
o) in series and connected to GND (earth).

Also, the collector of the transistor (Q, o) is connected to the reference resistance (R
．． ref'), connected in series with the reference diode (Dref'), and connected to the supply power VCC. Next, click on the diagram to explain the operation of the transistors (Qo I), (Q.o).
The respective junction areas SfhSO and emitter current I
o1%rref' is different, especially the bonding area is SO
>SoI, therefore the transistor (Q.
o+) and (Q.O), the base-emitter voltage J HE01J BED is . T R E0
1 = k'r/l nj history -- (1) Q So1
, Is J RF,. =kT/In”'
It is expressed as ・=(2)9 SυWork8. Here, T: absolute temperature, k: PoI Retzman's constant, q: Cowan's constant, and 8: saturation current. The bases of transistors (Qo) and (Qo+) and GN
Since the voltage between D is the same potential, JRgo+ = Jsco +RO ・Iref'
・la) Therefore, Irer=”ε111-J-BEIJ=1.kT
/(, (ul. 9'J, Kg, Ro R
o Q Snl-Is Iref' = Shame. kT/
1rISo/S. ．． , Io 17. ,,,,
,,・(4) It is expressed as q. Here, if Io + >> Iref...(6) The reference current Iref' is determined by dividing the difference voltage (.; JHpo) between JBgo+ and JRE by the resistance (Ro). , the temperature coefficient of the reference current Iref is 6
(Formula) shows that it has a positive value. In Figure 3, the above T-proportional criterion 1! i5fE Ir
ef, reference resistance (Ref'), reference diode (Dr
Between the supply [fiVcc and the low potential point of the reference resistor (Rref), point X shown in the diagram],
The generated voltage Jref is . TB(Dref')=kT/ln-'-E! -! −
-(7)q Sref-Ia Jref = Iref -R ref' +JBB(
Dref') = 48). Here, Sref represents the junction area of the reference diode (Drew), and Is represents the saturation current.

Here, vHE usually has a negative temperature coefficient and a reference resistance (R
．． ref) usually exhibits a positive temperature coefficient.

Therefore, in equation (8), the first term (Iref'Rre
Since the temperature coefficient of the reference current Iref is positive from equation (6), f) has a positive temperature coefficient, and since the second term has a negative temperature coefficient, the added reference voltage hef is Temperature compensated, reference resistance (Rref'), and Xrd
Appropriate setting of %Sref results in a voltage with almost no temperature coefficient.

[Problems to be Solved by the Invention] Since the conventional reference voltage generation circuit is configured as described above, the positive temperature coefficient of the term (Iref'-Rref) multiplied by equation (8) and the reference diode The negative temperature coefficient provides a stable, temperature-compensated reference voltage;
), the absolute value of the reference diode is influenced by the value of the voltage Jref', I
In the case of C, the base-emitter voltage JRg (Dref') of the reference diode usually has a value of ±5 to ±10q5 during mass production due to variations in impurity diffusion concentration, etc. There was a need for improvement as a high-precision reference voltage circuit.
In addition, the reference diode and (Irer-Rref
) term and the collector-emitter of the transistor (Qo) are connected in series, so the minimum voltage of the supply voltage Vcc required to operate the reference voltage generation circuit of FIG. 3 is equal to the diode voltage (;0. 6V) and (Rref'I
ref): 0.5 ~ 0.6 V 11cpH (Q
o): There was a drawback that the sum of 0.2 V required approximately 1.3 to 1.4 V or more. This invention was made to solve the above problems and drawbacks. It is an object of the present invention to provide a reference voltage generation circuit which can reduce variations in the absolute value of the reference voltage and reduce the minimum supply voltage of the reference voltage generation circuit (to less than 1O).

[Means to solve the problem]

The reference voltage generation circuit according to the present invention does not use a reference diode and is determined only by the product of the reference resistance and the reference current, and the reference current setting is determined by the conventional JREO difference (
In addition to the current determined by iJB12) and the resistor, an additional circuit is configured with two current generating circuits determined by the difference in JBE (4JBε) and the resistor, and the difference current between the above current generating circuits is [Operation] This invention makes use of the fact that the current determined by the Jago difference and resistance in the conventional circuit has a positive temperature coefficient according to equation (6). Moreover, by utilizing the fact that the positive temperature coefficient value changes depending on the magnitude of the difference in base-emitter voltage, which is determined depending on the junction [fi product or emitter current] of the transistor to be constructed, By subtracting the current of the current generation circuit with a large positive temperature coefficient from the current of the current generation circuit with a small positive temperature coefficient, the temperature coefficient of the subtracted current is made negative. Furthermore, by applying the current obtained by adding the above Io and the above subtracted current to the reference resistor as a reference current, temperature compensation is achieved, and by not using diode gold, a low operating power supply with less fluctuation in the absolute value of the reference voltage is achieved. Voltage reference voltage generation circuit gold can be obtained.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings. 1st
The figure is a circuit diagram of a semiconductor integrated circuit reference voltage generation circuit. Click on the diagram and select (Ion) + (Qo). (Qo+
)+(Ro) and (Rref') are the same as those shown in the conventional example of FIG. 3, so their explanation will be omitted. (I
o2) is a current source, (Qo2), (Q3) ~ (Q +
n) is a transistor, . R1) to (R3) are resistors. Current source (Io+), common base connected transistor (QOI), (Qo) and U} transistor (Q
The circuit consisting of a resistor (RO) connected to the emitter of υ) is similar to the conventional circuit shown in FIG. In the circuit of FIG. 1, in addition to this, the current i1JA (IO2), the diode-connected transistor (Q, o2), the transistor (q. QIO) and a transistor (Q9
)． (Q.Hl) between each emitter and GND,
Resistor for current setting (Rl). (R2), and the base-emitter voltage JBEO of the transistor (qo2)
2 and the base of transistors (Q9) and (q+o) -
The collector of the transistor (Q10) is a diode-connected p
Connected to the collector base of the Dp transistor (Q5). Also, ppp transistors (qs), (Qa
) constitutes a common base and common emitter connected current mirror circuit. The collector of the transistor (Q!), which is the current mirror circuit output, is connected in series with the output of the constant current source (Iol), that is, the collector of the npn transistor (Q9), and the connection point (Y shown in Figure 1) is connected in series with the collector of the npn transistor (Q9). point) is connected via a resistor (R3) to a current mirror circuit constituted by transistors (Q?) and (Q8) whose common base and common emitter are connected. The collector of the transistor (Q8) that serves as the current mirror circuit output is connected to a constant current source (I
o1) is commonly connected to the collector of the transistor (QO) and connected to one end of the reference resistor (R~0).The other end of the reference resistor (Rref) is connected to the supply power Vcc.

Next, the operation will be explained.

In Fig. 1, a constant current source (
The current of Iol) is the reference current of the conventional example shown in Fig. 3.
By performing the same operation as ', the absolute value and temperature coefficient are expressed as in equations (5) and (6) above, and the absolute value of the current Io is the transistor (QOI), (Q, o). J
It is determined by the difference in RE and resistance (Ro), the temperature coefficient of Io is positive, and the ratio of junction area (SO/So.
).

Generally speaking, the base-emitter voltage JRE of a transistor
．． The temperature change of the base-emitter voltage difference is qualitatively shown in FIGS. 4 and 5, respectively. J.
The larger the absolute value of ε, the smaller the negative temperature coefficient of JBE, and the larger the JBEo difference (JBx) 'Ell pressure, the larger the positive temperature coefficient of aJHE.

In this invention, at least three types (three sets) of circuits with different junction area ratios are prepared for the constant current source circuit determined by the J8ε voltage difference and the resistance, and each constant current source circuit is Set a positive temperature coefficient value of 3fii or more. As a result, by subtracting the constant current source circuit current with a large positive temperature coefficient from the constant current source circuit with a small positive temperature coefficient, a constant current source with a negative temperature coefficient is generated. , In FIG. 1, the transistor (Qo+),
(Q.o) , (Qo2) , (QQ), (Q+
The base-emitter junction area of each base-emitter of 8111 .
80, 802, Sol, S1fl, a constant current source (Io+) composed of transistors (Q, *), (Qca), and a transistor (q+n
) , (Q,02) constant current source (Io2)
What is the current value of each? It is expressed as kT S" 工2 skewer 4■/q1rl ichi ko, ~.

...(1l) Here, let each junction area be SIO >89>So or 8゜゜/8.2〉S9/8.2, ...02) ...(13) Now, the ambient temperature Ta Currents II, I2, I
When the change characteristics of No. 3 are shown in Figure 2, the current setting resistor (
R2), (Rl) so that I2 > I+
If l>R2 is set, as shown in Fig. 2, the temperature change of the constant current sources (Io2) and (Ion) is large, and
Further, the absolute value can be set to a characteristic that has a large factor 2.

Transistor (Ql1
)(qs)
Output the same current from the collector of the transistor (Q6), and connect it in series with the collector output terminal 1 of the transistor (Q5), resistor (R3), and transistor (Q7').
, (Q8) From the current mirror circuit constructed by
:Outputs the current of 2-41.Here, as is clear from FIG. 2, I3 has a negative temperature coefficient that decreases as the temperature rises.

The current I3 generated in this way and the transistor (
JOE difference of Q, o+ ), (Qo) and resistance (RO)
The currents IO of the constant current sources having a positive temperature coefficient, which are set at the value of , are summed and combined and applied to the reference resistance (Hrer) at the points shown in FIG. Therefore, the reference resistance (Rrer
) The reference voltage Jref' generated at the rlfii terminal is Jrer = rrer - Rref' = Rref' ( I
B+I3). Rre c(kT/q..4 1rlS,
'． '、． Jd'/. l41.1,. S. '． He'i
``The temperature coefficient of the set reference voltage Jrer is aJre tT$k/q (R.r.e rlrl
Nyuuichi R, re CM. 4 +R. r. e'In
Sn. , ) , ,・i15) From this, Engineering・Insei + Earth・Tosho = 1・1n gong ・・・(
16) R2 902 }10 801 RI
By setting the currents of C, II, and I2 so as to satisfy the conditions of Sn2, the temperature coefficient of the reference voltage applied to this invention can be set to almost zero. The circuit is the third
A reference diode (nre) as seen in the conventional circuit shown in the figure
r), and as shown in equation (14), setting 1 [
Pressure d, ffi Anti-noise ratio (Rref/R2, Rr”/H
, ． ``'/,o) Since the structure is set by the ratio of the junction area and the junction area, it is possible to provide a stable reference voltage generation circuit with little fluctuation, and at the same time, it can also supply the minimum operating voltage.
Since it is composed of an active element connected in series between CC and GND, or the sum of the base-emitter voltage of one transistor and the collector-emitter voltage, the voltage is approximately 1 V or less, which is a significant improvement compared to conventional circuits. However, the above embodiment is a JBE difference (J.TH) based on a Ropo} transistor.
E) and a constant current circuit using a resistor were explained, but pn
It can also be realized by a combination of a constant current source circuit based on p} transistors, or a constant current source circuit based on fIpT3 transistors. It can also be realized and applied by a combination of constant current source circuits based on pnp transistors.

In addition, in this invention, the method of combining the voltage difference between VBg and the current source set by the resistor is as follows: It can also be widely applied.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to provide a reference voltage circuit that can be almost determined only by the resistance ratio and the junction area ratio, which does not include the absolute value of the diode voltage, and the manufacturing deviation of the absolute value can be extremely suppressed. , high precision reference voltage can be changed. At the same time, by adjusting the positive and negative temperature coefficients, the reference voltage is completely temperature compensated, and the minimum operating voltage is also
It is possible to lower the voltage by about 0.5v compared to the conventional circuit, making it ideal for applications with low power supply voltage such as Battery Ace equipment.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of a semiconductor integrated circuit reference voltage generating circuit according to an embodiment of the present invention, and FIG.
3 is a circuit diagram of a conventional reference voltage generation circuit. 4 is a graph showing the temperature coefficient of the base-emitter voltage VBE of a general bipolar transistor. 5 is a graph showing the temperature coefficient of the base-emitter voltage VBE of a general bipolar transistor. This is a graph showing the temperature coefficient of the base-emitter voltage difference jVRε of a transistor (In+). (Io2) is a current source, <Qa)
, (Q,or) , (Q,o2) , (Q3
) ~(Q]O> is a transistor. (RO) ~(R
The resistance of the three companies (Rret) is probably the standard resistance, and in the diagram, the same reference numerals indicate the same or corresponding parts. Substitute Masao Oiwa Masao (self-motivated) Heikai@@2 February 19 Incident Patent applicant address 2-2-3 Marunouchi, Chiyoda-ku, Tokyo Name (601) Mitsubishi Electric Corporation Representative Shiki
Moriya 4. Agent address: 2-2-3 Marunouchi, Chiyoda-ku, Tokyo 5. Detailed description of the invention and drawings in the specification to be amended. 6. Contents of amendment (1) “Ran resistor (Qo1
), (QD) is ``ransistor (QOI), (Q
O) is corrected as 0 (2) "q: Kuwan's constant," on page 4, line 2 of the specification.
" is corrected to "q: Coulomb's constant,". (3> Correct “(10 or less)” on page 6, line 19 of the specification to “(1.0V or less)”. (4) “Constant current source (Io1)” on page 9, line 11 of the specification
) Correct J to “Constant current source (I1) J” 0 (5) Correct “Constant current source (Io!),” on page 11, line 11 of the specification to “Constant current source (I1),” do. (6) “Constant current source (IO2)” on page 11, line 12 of the specification
” to “Constant current source (I2) J” 0 (7) Specification page 11, lines 18 to 19 “810) 89) So
・・・○Also 810/s02》s
o/802 ・Q3 J to “S9)810:>So −(
Inl or S 10 /So 2 (( 8 e/
Correct it as So 2 − Q3 J. (8) “Constant current source (Io2),
(Ion) J is corrected as ``constant current source (I2). 0αO Correct Figure 1 of the drawings in the attached sheet. 7. List of attached documents (1) Corrected drawings (Figure 1) 1 or more copies of Figure 1 JOT, IO2/Takuraigen Q6, Qo+, Qoz ,Qs~Olo : }Rangister scale 0~shaku j Saijit Rref Reference #, Pile

Claims (1)

[Claims] In a bipolar semiconductor integrated circuit in which a bipolar transistor with an emitter, a base, and a collector, a diode with an anode and a cathode, a resistive element, etc. are integrated on the same semiconductor substrate, the junction area between the base and emitter of the integrated transistor , or the emitter current value,
The transistors are set to at least three different values and have at least three different base-emitter voltages J_B_E_n, and the two transistors with different base-emitter voltages are connected to a common base. Differential voltage ΔJ_B of base-emitter voltage J_B_E_n
_E_n, and at least three current generating circuits An each having a resistive element connected in series to the emitter of one of the two transistors and outputting a current from the collector. After subtracting the output current I_0 of the set of current generating circuits Ao and the output currents I_1 and I2 of the two sets of current generating circuits A_1A_2, the determined current (I_n-I_2) is added and output. The reference current Iref is applied to a voltage setting resistance element, and the voltage across the voltage setting resistance element is set as the reference voltage. A semiconductor integrated circuit reference voltage generation circuit.