JPS5930029A - Temperature detecting device - Google Patents

Abstract

PURPOSE:To obtain high accuracy and to decrease costs, by making a one conducting type semiconductor substrate a common collector, specifically connecting the connecting initial stages and final stages of at least two transistors, which are connected in a Darlington mode, thereby constituting a temperature detecting part. CONSTITUTION:For example, two N-P-N transistors 14 are connected in a Darlington mode. The base of the transistor 14 in the initial stage is connected to a common collector and a first electrode is formed. The emitter of the transistor 14 in the final stage is made to be a second electrode. Thus a temperature detecting part is constituted. A constant current circuit 8 is connected to the second electrode. Then a temperature sensor part A of the N-P-N transistor is formed by a collector electrode 23, a base electrode 17, and an emitter electrode 18. In this case, a P<+> diffused layer 20, which is to become a base region, can be manufactured together with a substrate region 27 of an N channel transistor B. An N<+> emitter region 22 can be manufactured together with a source 26 and the like of the transistor B.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a highly sensitive temperature sensor formed by connecting two or more bipolar transistors using a common collector on a semiconductor substrate, and a constant current circuit that supplies a constant current to the sensor on the same substrate. The present invention relates to the temperature detection device manufactured above.

Conventionally, elements and systems for detecting temperature, for example,
A circuit configuration as shown in the figure is used.

Its operating principle is that a resistance value detection circuit 2 detects a change in resistance value due to temperature of the thermistor 1, and a signal from a control output terminal 6 turns the transistor 4 on and off.
Heater 50 heat generation core 1-.

- We have adopted the method of The disadvantage of this method is that the thermistor deteriorates significantly and is not very reliable.

The characteristics of the thermistors vary widely, and it is necessary to adjust each element using the adjustment resistor 6 so that it is detected at a predetermined temperature. Furthermore, the number of parts is large, the cost is high, the reliability is low, and a large space is required. There are drawbacks such as.

Further, as another temperature detection element, there is a circuit as shown in FIG. 2 which supplies a constant current to a PN junction diode 7 and measures the temperature change in the output voltage 9. However, this temperature sensor normally only provides an output voltage of 2 mv/'C with a single diode stage, so in order to achieve an accuracy of 1°C through A/D conversion, the subsequent circuit must be made with high precision. Ta. Commercially available PN junction diode temperature sensors include:
As shown in Figure 3, a circuit is used in which the pace and collector of an NPN) run shifter are connected, and the current is usually several 100 μA.
It is necessary to supply a current of several mA from an external source, and this current causes self-heating and increases measurement errors. In addition, in Fig. 3, 10 is the collector,
11 is a base, and 12 is an emitter. Conventionally used temperature sensors have the above-mentioned drawbacks, and there has been a long-awaited temperature detection device that is stable, highly accurate, and can be manufactured at low cost.

The present invention eliminates the above-mentioned drawbacks of the conventional technology and provides a low-cost, high-axis temperature detection device using a completely new system. The main point of the present invention is to use two N P N transistors.
A high-sensitivity temperature sensor connected to Darlington and a constant current circuit that supplies a constant current to it are all mounted on the same board.
It is created at the same time as the MO8fA manufacturing process, so there is no need for a special process to incorporate the temperature sensor. Including the temperature sensor and constant current circuit, the board area is extremely small.The constant current value supplied by the 0MO8 constant current circuit is about Aooo compared to the conventional one, and the error due to self-heating is small. This eliminates the drawbacks of the conventional method.

Hereinafter, the present invention will be explained in detail using the drawings.

FIG. 4 is a circuit diagram in which a constant current circuit 8 is connected to a circuit in which two NPN run shifters used in the present invention are connected in Darlington. NPN) 6mv/℃ with two run shifters,
In FIG. 5, which is an improved version of FIG. 4, three transistors have a temperature sensitivity of 11 mV/°C. 15 is an output terminal. This new temperature sensor built into 0MO8 will be temporarily installed at H Engineering TEI.
e-emperature
It is called dansensor). 8 is a CMO8 constant current circuit to be described later, which is a circuit for supplying a constant current of 0.2 μA to the H engineering TE, and this circuit is connected to the H engineering TS together with the C! M.O.
The key point of the present invention is that it can be incorporated into the 81 chip.

Figure 4, sentence 51, and Figure 6 are the same-C used in the present invention.
This is an example of a circuit diagram of a temperature detection device fabricated on a MOS chip. 4 shows a two-stage connection of the NPN) run shifter 14, FIG. 5 shows a three-stage connection, and FIG. 6 shows a three-stage connection.
A structure is provided in which the current amplification factor β is reduced to reduce variations in the output voltage yy and the output terminal 15, and to obtain a stable output against external noise. FIG. 7 shows that the one-chip temperature detection device used in the present invention has the same C! FIG. 3 is a cross-sectional view of the structure showing that it can be manufactured using a MOS process. In the figure, region A is a structural cross-sectional view of an NPN run shifter, region B is an N-channel transistor, and region C is a P-channel transistor. In the figure, 20idNPN) is a P+ diffusion layer which becomes the base region of the run shifter, and can be formed at the same time as forming the P well of the N-channel transistor, that is, the substrate region 27.

The N+ emitter region 22 is the source 26 of the N-channel transferer. When the NJ diffusion layer of the drain 25 is reversed, it can be manufactured at the same time.

21 is a base contact P+ region, and 41 is a collector contact N+ region. Here, 23 is a collector electrode, 1
7 is a 3-sence electrode, and 18 is an emitter electrode. I'm scared
The power sensor part A is formed.

In the same N-channel transistor part B, 39 is a gate insulating film, 2'4 is a door channel cut, 25 is an N+ drain,
26 is N+ sauce. Further, 35 is a drain electrode,
65 is a source electrode. P channel transistor section C
29 is an N+ channel cut, 30 is an N+ drain, 31 is an N+ source, 39 is a gate insulating film, and 3
6 is a drain/electrode, 37 is a gate electrode, and 38 is a source electrode.

As mentioned above, the H-TEI temperature sensor is a normal CM
It can be created at the same time as other (3MO8) circuits in the OS process.
cuoe that supplies minute current without requiring complicated processes
A major feature is that it can be configured on the same chip as the constant current circuit.

Next, the CMOB constant current circuit used in the temperature detection device of the present invention will be explained. FIG. 8 shows the circuit diagram.

The details of the principle of this circuit are omitted here, but the circuit is simple and suitable for reducing current consumption because it does not include a comparator or constant voltage circuit, which are normally used in constant current circuits. be. The constant current value of this circuit is
It is determined by the following formula.

Ir5f=K(1(VTpH-VTPL)"where, K
o is KM (conductance constant) of the transistor 45, VTPII fi ) is the threshold of the run shifter 42,
vTPT- is the threshold value of the transistor 41, which is lowered by ion implantation or the like. In other words, this circuit C,
Since the constant current value is determined by the product of the conductance constant of the transistor 45 and the difference between the two threshold voltages, a constant current with little variation can be obtained. In FIG. 8, 46 is a load such as the H engineering TS temperature sensor. 44 and 43 are N-channel transistors whose threshold value and conductance constant are equal, and 45 is a transistor whose constant current value is determined by its conductance constant. 47 is a power source.

FIG. 9 is a graph of the power supply voltage dependence of the constant current value obtained by this constant current circuit. The 10th @ is )1'
FIG. 1 is a circuit diagram of a first embodiment of the present invention in which a 1TEL temperature sensor and a 0M0B constant current circuit are integrated on the same chip. 48
The area within the frame is the constant current circuit, and 501) Z HI T S!
fl-+ 7”j” T: Yes. 51 is V'DD.

55 is yss, and 52 is the output voltage terminal 7F.

FIG. 11, which is a second embodiment of the present invention, is a circuit diagram in which the circuit of FIG. 10 is further integrated with a voltage comparison circuit and an output/(sofa) on the same chip. In the figure, a 59Fi voltage comparison circuit, 58 is the output) (sofa, 53 is the input voltage terminal, 54
is the output terminal. We are using this one-chip IC as 11f.
It was integrated into the i corner.

FIG. 12 is a graph showing temperature changes in the sensor output, with temperature on the horizontal axis and output voltage vy on the vertical axis.

As described above in detail, according to the present invention, the temperature sensation is 411 m
v/℃, and a very small temperature sensor (HITS), a 0MO8 constant current circuit that supplies a minute constant current of about 0.2 μA, a voltage comparison circuit, an output buffer circuit, etc. Using CMOS process, it can be integrated into the same chip without requiring any special process, and has high sensitivity,
This temperature detection device has the features of low power consumption, small variation, high stability, and low chip cost. This temperature detection device!
h Due to the above characteristics, it can be used as a temperature detection device in place of conventional thermistors and bipolar temperature sensors.

[Brief explanation of the drawing]

Figure 1 shows the circuit diagram of an example of a temperature detection system using a M type thermistor. 2 and 3 are circuit diagrams of a conventional diode temperature sensor and an NPN) run shifter temperature sensor, respectively. FIG. 4 is a circuit diagram of a two-stage Darlington connection sensor used in the present invention, and FIG. 5 is a circuit diagram of a three-stage Darlington connection sensor used in the invention. FIG. 6 is a circuit diagram of a six-stage Darlington connection sensor with a multi-collector structure used in the present invention. Figure 7 shows the H-TS temperature sensor used in the present invention. Structural cross-sectional views of an N-channel transistor and a P-channel transistor. FIG. 8 is a circuit diagram of a CMO8 constant current circuit used in the present invention. FIG. 9 is a graph showing the constant current characteristics of the circuit shown in FIG. 8. FIG. 10 is a circuit diagram of the same chip temperature detection device according to the first embodiment of the present invention. FIG. 11 is a circuit diagram of a second embodiment of the present invention. FIG. 12 shows the output voltage terminal obtained by the temperature detection device of the present invention. 48... Constant current circuit 50... H engineering TEI temperature sensor 51...
...VT)D 55...yes 52...Output voltage terminal 59...Voltage comparison circuit 58...Output buffer 55...Input Voltage terminal 54... Output terminal or higher Applicant Daini Seikodai Co., Ltd. Figure 1 Figure 2 Figure 4 w43 Figure 9 Figure 1O Figure

Claims (2)

[Claims] (1) - A conductive type semiconductor substrate is used as a common collector, and the base of the transistor in the first stage of Darlington connection is connected to the common collector, and the first electrode and none,
Connect the emitter of the final stage transistor to the second Darlington connection.
1. A temperature detection device comprising: a temperature detection section having an electrode; and a constant current circuit connected to the second electrode to supply a constant current. (2) a circuit in which a first insulated gate field effect transistor having a first conductivity type and a second insulated gate field effect transistor having a second conduction type are connected in series; a sixth insulated gate field effect transistor of a first conductivity type whose threshold voltage is different from that of the insulated gate field effect transistor; and a fourth insulated gate field effect transistor of a second conductivity type whose threshold voltage is equal to that of the second insulated gate field effect transistor. A circuit in which two insulated gate field effect transistors are connected in series are connected in parallel to a power supply, and the gate electrodes of the first and fifth insulated gate field effect transistors are connected to the sixth and fourth insulated gate field effect transistors. connecting the gate electrodes of the second and fourth insulated gate field effect transistors to the junction of the first and second insulated gate field effect transistors; A constant voltage circuit is configured, and a circuit in which a fifth insulated gate field effect transistor is connected in series to the load is connected in parallel to the power supply, and the gate electrode of the fifth insulated gate field effect transistor is connected in parallel to the power supply. 2. The temperature detection device according to claim 1, wherein a constant current is supplied by a constant voltage circuit connected to a constant voltage output of said constant voltage circuit.