JPH0425767A - Temperature characteristic compensation device for semiconductor device - Google Patents

Abstract

PURPOSE:To perform compensation without using any temperature sensor and to facilitate adjusting operation by providing three resistors among three terminals to which voltages signals of different temperature characteristics including zero are applied. CONSTITUTION:In a constant current circuit 200, a bridge circuit 100 which is supplied with a constant current transduces pressure into an electric signal by utilizing piezoelec tric effect and a correcting circuit 300 generates a temperature correction signal for temperature compensation. An adding circuit 400 adds the pressure signal of the circuit 100 to the temperature correction signal of the circuit 300 to compensate the tempera ture characteristic of the pressure signal from the circuit 100 and an amplifying circuit 500 amplifies and output the signal. At this time, one-terminal sides of the resistors R9 - R11 in the circuit 300 are connected to a terminal (d) where the voltage having the largest temperature characteristic is applied, the ground of 0 potential with the least temperature characteristics, and the resistance terminal of the circuit 400 where a voltage with an intermediate temperature characteristic is applied. For the purpose, the resistor R9 or R10 is trimmed to enable and facilitate the adjusting operation for the temperature characteristic of a temperature characteristic compensating current flowing to the resistance 11.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a temperature characteristic correction device for a semiconductor device that corrects the temperature characteristics of a signal output from a semiconductor device.

[Prior art] In devices using semiconductor elements, such as semiconductor pressure sensors,
Because the output signal changes depending on the ambient temperature due to the temperature characteristics inherent in semiconductors, it is necessary to correct the temperature characteristics of the output signal. Generally, the ambient temperature is detected using a temperature sensor such as a thermistor, and the detection result is Based on this, the output signal of a semiconductor device is corrected. Furthermore, in order to perform temperature compensation without using a temperature sensor, it has been proposed to provide a temperature compensation resistor in a semiconductor device, as described in Japanese Patent Publication No. 62-55629, for example.

[Problem to be solved by the invention] If the temperature characteristics of the semiconductor device are corrected using a resistor as in 2, the temperature sensor becomes unnecessary and the circuit configuration can be simplified. In the device of
The mounting position of the temperature compensation resistor must be changed depending on the temperature characteristics of the semiconductor device, which poses a problem in that the adjustment work of the correction circuit becomes complicated.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a temperature characteristic correction device that can correct the temperature characteristics of a semiconductor device without using a temperature sensor, and can easily perform the adjustment work.

[Means for Solving the Problems] That is, the present invention, which has been made to achieve the above object, is a temperature characteristic correction device for a semiconductor device whose output characteristics change depending on the ambient temperature, and which includes three types including large, medium and small. Three terminals to which voltage signals having different temperature characteristics were applied; Among the three terminals, a terminal to which a voltage signal with the largest temperature characteristic was applied, and a terminal to which a voltage signal with the smallest temperature characteristic was applied. Two resistors whose resistance values can be adjusted by trimming are connected in series between the two resistors, the terminal to which a voltage signal with intermediate temperature characteristics is applied among the three terminals, and the two resistors connected in series. a fixed resistor connected between the connection point of the resistor and having a resistance value a predetermined times greater than the resistance value of the two resistors; and correcting the output signal from the semiconductor device based on the current flowing through the fixed resistor. The gist of the present invention is an apparatus for correcting temperature characteristics of a semiconductor device, characterized by comprising a correction means.

[Functions and Effects of the Invention] As described above, in the temperature characteristic correction device of the present invention, three Y-connected resistors are connected to the three terminals to which voltage signals having different temperature characteristics are applied, and the temperature Two resistors connected between the terminal to which the voltage signal with the largest characteristic is applied and the terminal to which the voltage signal with the smallest temperature characteristic is applied can be trimmed, and another resistor can be trimmed between the two resistors. A fixed resistor having a resistance value a predetermined times larger than the resistance value of the resistor is used, and the pressure signal from the semiconductor device is corrected based on the current flowing through the fixed resistor.

Therefore, by trimming one of the two trimmable resistors and adjusting its resistance value, it is possible to arbitrarily set the temperature characteristics of the current flowing through the fixed resistor, and this current By setting the temperature characteristics of the value according to the temperature characteristics of the output signal from the semiconductor device,
Using this current value, it becomes possible to easily and accurately compensate for the temperature of the output characteristics of the semiconductor device.

"Example] Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an electrical circuit diagram showing the overall configuration of a pressure detection device according to an embodiment of the present invention.

As shown in the figure, the pressure mixing device of this embodiment includes a bridge circuit 100 that converts pressure into an electrical signal using the piezoresistance effect of a semiconductor, and a constant current circuit 200 that supplies a constant current to this bridge circuit 100. , a correction circuit 300 that generates a temperature correction signal for correcting the temperature characteristics of the pressure signal output from the bridge circuit 100, and the bridge circuit 10.
an addition circuit 400 that corrects the temperature characteristics of the pressure signal from the bridge circuit by adding the pressure signal from 0 and the temperature correction signal from the correction circuit 300;
The amplification circuit 500 amplifies the temperature-corrected pressure signal output from the 00 and outputs an external pressure.

First, the bridge circuit 100 includes four diffused resistors Ra, Rb, Rc, and R that constitute a semiconductor pressure sensor.
It is composed of d. The bridge circuit 100 also includes resistors R1 and R2 for correcting unbalanced voltages occurring at the output terminals S and C. The relationship between the above resistances is as follows: Ra Cape Rb Average Rc = Rd, Ra (R7,
Ra<<R8.

On the other hand, the constant current circuit 200 includes resistors R3, R4°R5,
A constant current 10 determined by the reference voltage 0 obtained by dividing the power supply voltage Vcc by resistors R3 and R4 and the resistance value of the resistor R5 is connected to the positive terminal side of the bridge circuit]00. Supplied from terminal a side.

Next, the adder circuit 400 converts the voltages Vb and Vc generated at the output terminals S and C of the bridge circuit 100 into an operational amplifier ○P.
2. resistor R through the buffer configured by OP3
The voltage difference (Vb-Vc) is converted into a current IR61m flowing through a resistor R6, thereby generating a pressure signal. Further, a correction circuit 300 is connected to this addition circuit 400, which adds the pressure signal IR6 generated above and a temperature characteristic correction signal lR11, which will be described later, generated by the correction circuit 300, and amplifies the signal through a transistor TRI. The signal is output to the circuit 500.

Next, an amplifier circuit 500 (consisting of one resistor R7, R8 and an operational amplifier ○P4) outputs a voltage signal corresponding to the current (IR6+IR11) flowing through the adder circuit 400 as a detection signal.

Next, the correction circuit 300, which is the main part of the present invention, is composed of three EY-connected resistors R9, RIO, and R11. Further, the resistance values of the resistors R9 and RIO can be adjusted by trimming, and one end of the resistor R9 is connected to the negative terminal C of the bridge circuit 100, and one end of the strip resistor RIO is grounded. In addition, resistor R9, RI
The resistance values of O before trimming are set to the same value.

On the other hand, the temperature characteristic correction signal lR11 flowing through the resistor R11 is connected to the current I flowing through the resistors R9 and RIO.
R9,l is made up of a fixed resistor having a resistance value approximately 20 times the resistance value of RIO. It is connected to the vb side terminal of resistor R6.

In the pressure detection device of this embodiment configured in this way, the connection point voltage of each resistor in the correction circuit 300 is set to Vf.
Then, the pressure voltage VOUTi representing the pressure detection result output from the amplifier circuit 500 can be written as shown in the formula (1), VOUT = R7 (V b - V c) / R9 + R7 (V
b-Vf)/R11... (1) VOU to its temperature characteristics
T E is as shown in the following equation (2).

ΔVOLIT=R7(AV b-AV c)/R9+
R7(AV b-AV f)/R11=-(2) Here, the first term on the right side of equation (2) is the bridge circuit 100.
That is, it is the temperature characteristic of the semiconductor pressure sensor, and the second term on the right side is the temperature characteristic in the correction circuit 300. Therefore, in order to take advantage of the temperature characteristics of the output voltage VOUT, the correction circuit 30
The temperature characteristics of the bridge circuit 100 may be corrected based on the temperature characteristics at zero.

By the way, in the second term on the right side of the above equation (2), if the voltage at the negative terminal d of the bridge circuit [00] is Vd and its temperature characteristic is △Vd, △Vf can be written as the following equation, △Vf= The temperature characteristic Δvb of ΔVd−R10/(R10+R9)vb is about half the temperature characteristic of Vd (Δvb2ΔVd/2) because vb is taken out from the middle of the bridge circuit 10o.

Therefore, the second term on the right side of equation (2) above can be written as
It can be seen that temperature correction can be performed satisfactorily by trimming the IO and adjusting its resistance value.

That is, in this embodiment, since the initial setting is 1iR9=R10, as shown in the following table, the temperature characteristic ΔlR11 of the temperature characteristic correction current lR11 is a treasure, and the resistor R
9 becomes 1iR9>Rloo, and the temperature characteristic ΔR11 of the temperature characteristic correction current 1R11 becomes positive. Conversely, if the resistor RIO is trimmed, R9<RIO becomes 1iR9>Rloo, and the temperature characteristic ΔR11 of the temperature characteristic correction current 1R11 becomes positive.
becomes negative.

Therefore, if the temperature characteristic ΔVOUT of the output voltage VOUT is positive, the correction circuit 300 trims the resistor RIO.
On the other hand, if the temperature characteristic of the output voltage VOtlT is negative (by trimming the resistor R9 and making the temperature characteristic of the correction circuit 300 side, that is, ΔlR11, positive), Output voltage VO
It becomes possible to temperature compensate the UT.

In addition, to adjust the temperature characteristics, first adjust the resistors R9 and R.
Before trimming IO, the temperature characteristic ΔVOUT of the output voltage V OUT is actually measured to determine the temperature characteristic of the bridge circuit 100. Based on this temperature characteristic, the voltage Vf at the connection point of each resistor in the correction circuit 300 is calculated by the following formula ( 3) The resistor R9 or R10 may be trimmed so that
/(R9+R10)V d)
.

As explained above, the pressure detection device of this embodiment (in the second embodiment, the correction circuit 300 is composed of three Y-connected resistors R9
~R11, and the negative terminal d of the bridge circuit 100, to which the voltage signal Vd with the largest temperature characteristic is applied to one end of the resistor R9, is connected to one end of the resistor R]O with the smallest temperature characteristic (O). Connect the ground at 0 potential to resistor R11.
are connected to the resistor terminals of the adder circuit 400 to which a voltage signal vb having an intermediate temperature characteristic is applied, and the resistor R
9. The resistance value can be adjusted by trimming RIO. Therefore, by trimming either one of the resistors R9°RIO, it is possible to adjust the temperature characteristics of the temperature characteristic correction current lR11 flowing through the resistor R11 in either the positive or negative direction. Adjustment work can be simplified.

In the above embodiment, the temperature characteristic of the output signal VOUT is corrected by adding the temperature characteristic correction current lR11 and the detection signal IR6 in the first table addition circuit 400. A circuit for correcting the pressure signal VOtlT applied from the amplifier circuit 500 based on the temperature characteristic correction current lR11 is provided, and the amplifier circuit 50
The output signal VOUT may be corrected at the subsequent stage of the output signal VOUT.

Further, in the above embodiment, the temperature characteristic correction current lR11 is generated using the voltage signals Vd, Vb having different temperature characteristics obtained by the bridge circuit 100 and the ground potential having no temperature characteristics. If it is not possible to compare voltage signals with different temperature characteristics from semiconductor devices, a voltage signal with different temperature characteristics is generated by the forward voltage of a diode or transistor, and this is used to adjust the correction current lR11. may be generated.

[Brief explanation of the drawing]

FIG. 1 is an electrical circuit diagram showing the overall configuration of a pressure detection device according to an embodiment of the present invention. ]00... Bridge circuit 200... Constant current circuit 300... Correction circuit 400... Addition circuit 5
00... Amplifier circuit R9, RIO, R11... Resistor

Claims (1)

[Claims] A temperature characteristic correction device for a semiconductor device whose output characteristics change depending on the ambient temperature, comprising three terminals to which voltage signals having three different temperature characteristics including zero are applied; Of the three terminals, the terminal to which the voltage signal with the largest temperature characteristic is applied and the terminal to which the voltage signal with the smallest temperature characteristic is applied are connected in series, and the resistance value can be adjusted by trimming. a resistor, and a tangent line between the terminal to which a voltage signal with intermediate temperature characteristics is applied among the three terminals and the connection point of the two series-connected resistors, and at least the two resistors A fixed resistor whose resistance value is a predetermined times larger than the resistance value of the semiconductor device, and a correction means for correcting an output signal from the semiconductor device based on the current flowing through the fixed resistor. Device