JP2721286B2 - Temperature compensation type reference voltage generation circuit for semiconductor device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a temperature-compensated reference voltage generating circuit for a semiconductor device, and more particularly to a temperature-compensated reference voltage generating circuit for a semiconductor device capable of canceling a temperature characteristic with an arbitrary output voltage. .

[0002]

2. Description of the Related Art In a semiconductor device having a transistor or the like which is a semiconductor active element, it is necessary to provide a temperature-compensated reference voltage generating circuit to compensate for a temperature drift.

FIG. 2 shows a conventional example of this type of temperature-compensated reference voltage generating circuit. Hereinafter, the circuit configuration and the operation will be described. Lines L1, L2, and L3 in which the following circuit elements are connected in series are connected in parallel between the power supply V _CC and GND. Of these, the MOS transistors M1 and M4 and the diode Q1 'are connected in series to the line L1, and the MOS transistors M2 and M5, the resistor _R0 and the diode Q2' are connected in series to the line L2.
Further, a MOS transistor M3 and a resistor R ₁ are connected to the line L3.
And a diode Q3 '.

Among the MOS transistors, MOS transistors M1, M2 and M3 are P-channel MOS transistors, and MOS transistors M4 and M5 are N-channel MOS transistors.

[0005] In such a circuit configuration, the diode Q1 ', Q2' to have a ratio to the emitter area of, by generating a bandgap voltage [Delta] V _BE across the resistor R _O line L
2 generates a reference constant current _IO . Then, the reference constant current I _O is supplied to the resistor R ₁ and the diode Q by a current mirror circuit.
3 'flows through a line L3 connected in series, and a reference voltage V _OUT is obtained via an output terminal connected to the line L3.

[0006] Now, the diode Q1 ', Q2' the ratio of the emitter area of 1: When n, bandgap voltage [Delta] V _BE generated across the resistor R _O is represented by the following formula (1).

[0007] _{ΔV BE = V T l n n} ... (1) where a _{V T = kT / q, k} : Boltzmann constant, T: absolute temperature, q: an electric charge of an electron.

[0008] The reference constant current I _O which is generated by the resistance R _O is represented by the following equation (2).

I _O = (V _T / R _O ) · ln _n (2) The reference voltage V _OUT is represented by the following equation (3).

V _OUT = V _BE + (R ₁ / R ₀ ) · V _{T1 n} n (3) Here, in order to set the temperature characteristic of the reference voltage generation V _OUT to 0 , the above (3) ) Needs to be partially differentiated with respect to the absolute temperature T, and the condition that becomes 0 must be given to the equation (3). That is, it is necessary to provide a condition satisfying the following expression (4) to the above expression (3).

[0011]

(Equation 1)

Accordingly, R ₁ , R ₀ ,
If n is selected, a reference voltage V _OUT having a temperature characteristic of φ can be obtained.

[0013] _{(R 1 / R 0) 1} n n = q / k × 2 [mV / ° C] (5)

[0014]

As described above, in the above-mentioned conventional reference voltage generating circuit, it is necessary to satisfy the expression (5) in order to obtain a reference voltage V _OUT having a temperature characteristic of φ. , (5) is a constant (= const)
Therefore, a constant value is obtained when (R ₁ / R ₀ ) l _n n ≒ 23.

Then, in the above equation (3), V _T
≒ 26mV (T = 300 ゜ K), V _BE ≒ 0.65 (T =
300 K), the reference voltage V _OUT is V _OUT ≒ 1.2
5 [V].

As described above, in the conventional reference voltage generating circuit, since the relationship between the reference voltage V _OUT and the temperature characteristic φ is uniquely determined, if a reference voltage other than 1.25 V is to be obtained, the temperature characteristic will be reduced. φ cannot be set. This means that the temperature characteristics cannot be canceled with an arbitrary output voltage, and there is a limit in improving the versatility of the reference voltage generation circuit.

The present invention solves the above-mentioned drawbacks of the prior art, and a temperature-compensated reference voltage generating circuit for a semiconductor device capable of canceling temperature characteristics with an arbitrary output voltage and improving versatility. The purpose is to provide.

[0018]

According to the present invention, there is provided a temperature compensated reference voltage generating circuit for a semiconductor device, comprising: a bandgap voltage multiplying circuit having a PNP transistor and a resistor; and a series connection to the bandgap voltage multiplying circuit. A resistor is provided, and a reference current is supplied to a connection circuit between the bandgap voltage multiplier and the resistor, thereby achieving the above object.

[0019]

As described above, a bandgap voltage multiplying circuit is constituted by the PNP transistor and the resistor, and the bandgap voltage multiplying circuit and a connection circuit composed of a resistor connected in series to the bandgap voltage multiplying circuit are provided. When the reference current is supplied, an arbitrary output voltage V _OUT capable of canceling various temperature characteristics can be obtained as shown by the following equation (8).

[0020]

Embodiments of the present invention will be described below.

FIG. 1 shows a circuit configuration of a temperature-compensated reference voltage generating circuit of a semiconductor device according to the present invention. Hereinafter, the circuit configuration and the operation will be described.

Lines L1, L2, L3 each having the following circuit elements connected in series between the power supply V _CC and GND.
Are connected in parallel. Of these, MOS transistors M1, M4 and a diode Q1 'are connected in series to line L1, and MOS transistors M2, M5,
The resistor _R0 and the diode Q2 'are connected in series. A MOS transistor M3 and resistors R ₁ , R _A , and R _B are connected in series to the line L3, and a PNP transistor (hereinafter, referred to as a PNP transistor) Q3 is connected to both ends of the resistor R _A.

[0023] The resistance R _A and R _B and the PNP transistor Q
3 and, multiplication circuit of the bandgap voltage V _B is formed. Among the MOS transistors, the MOS transistors M1, M2, and M3 are P-channel MOS transistors, and the MOS transistors M4 and M5 are N-channel MOS transistors.

In the above circuit configuration, the diode Q
By giving a ratio to the emitter area of 1 ′ and Q2 ′, a band gap voltage ΔV _BE is generated at both ends of the resistor R _O , and the line L2
, A reference constant current I _O is generated. Then, it flows to the series connection circuit comprising the reference constant current I _O and a resistor R ₁ and the multiplication circuit, finally the reference voltage of any output level through the output terminal connected to the line L3 V _OUT Have gained. The details will be described below.

[0025] Now, the ratio of the emitter area of the diode Q1 'and Q2' 1: When n, bandgap voltage [Delta] V _BE generated across the resistor R _O is represented by the equation (1), also the resistance R ₀ reference constant current I ₀ generated by the represented by the formula (2).

The output voltage (reference voltage) V _OUT is connected to the resistors R _A and R _B and the PNP transistor Q3 as described above.
Since this constitutes a multiplication circuit, the value shown in the following (6) is obtained.

[0027] _{V OUT = (R 1 / R} 0) · V T l n n + V BE (1 + R B / R A) ... (6) where, in order to make the temperature characteristics of the output voltage V _OUT and φ is the It is necessary to partially differentiate the equation (6) with the absolute temperature T, and to give a condition to be φ to the equation (6). That is, it is necessary to provide a condition satisfying the following expression (7) to the above expression (6).

[0028]

(Equation 2)

Therefore, if the above equation (7) is modified, the following equation (8) is obtained.

[(R ₁ / R ₀ ) · ln _n ] = [1+ (R _B / R _A )] × (q / k) × 2 [mV / ΔC] (8) Equation (8) above in, the right side [1+ (R _B / R _a)] is a variable. Therefore, according to the above equation (8), [(R
_{1 / R 0) · l n} n ] and [1+ (by appropriately selecting R _B / R _A)] of the relationship, it is possible to obtain an arbitrary output voltage V _OUT. That is, according to the temperature compensated reference voltage generating circuit of the present invention, an arbitrary output voltage V _OUT capable of canceling various temperature characteristics can be obtained.

[0031]

The temperature compensation type reference voltage generating circuit of the semiconductor device according to the present invention constitutes a band gap voltage multiplying circuit by using a PNP transistor and a resistor, and comprises the band gap voltage multiplying circuit and the band gap voltage multiplying circuit. Since the configuration is such that the reference current flows through the connection circuit formed by the resistors connected in series to the circuit, an arbitrary output voltage V _OUT capable of canceling various temperature characteristics can be obtained. Therefore, according to the present invention, the versatility of the reference voltage generation circuit can be remarkably improved.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a configuration of a temperature-compensated reference voltage generation circuit of a semiconductor device of the present invention.

FIG. 2 is a circuit diagram showing a conventional example of a temperature-compensated reference voltage generation circuit.

[Explanation of symbols]

L1, L2, L1 Line Q1 ', Q2' diode Q3 PNP transistor M1, M2, M3 P-channel MOS transistor M4, M5 N-channel MOS transistor R ₀ , R ₁ , R _A , R _B resistance

Claims (1)

(57) [Claims] 1. A bandgap voltage multiplying circuit having a PNP transistor and a resistor, and a resistor connected in series to the bandgap voltage multiplying circuit, and a connection circuit between the bandgap voltage multiplying circuit and the resistor A temperature compensation type reference voltage generating circuit for a semiconductor device, wherein a reference current is supplied to the semiconductor device.