JPS5852865A - Semiconductor integrated circuit device - Google Patents

Abstract

PURPOSE:To eliminate the change of the resistance temperature characteristic of a circuit affected by a resistance temperature characteristic substantially by keeping temperature in a chip constant in the semicoductor integrated circuit device containing the circuit. CONSTITUTION:When the resistance value of an external resistor Rf and an internal diffusion resistor R'' is equal, the collector currents of transistors Q1, Q2 are equal, voltage generated at the output terminal 3 of a comparison circuit 4 is low, currents hardly flow through the bases of the transistors of a temperature control circuit 5, and the temperature control circuit 5 does not elevate temperature in the chip. When the resistance value of the internal diffusion resistor R'' is made smaller than the external resistor Rf, the collector currents of the transistor Q2 increase, voltage at the output terminal 3 rises, currents flow through the bases of the transistors of the temperature control circuit 5, and temperature in the chip is elevated. The temperature rise continues until the resistance value of the resistor R'' equalizes to the resistor Rf, and stops at the point of time when the resistor R'' equalizes to the resistor Rf. When the resistance value of the internal diffusion resistor R'' is made larger than the external resistor Rf from the state, volage at the output terminal 3 further drops, the temperature control circuit 5 is not operated, and temperature in the chip is lowered.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a semiconductor integrated circuit device including a circuit affected by resistance temperature characteristics.

In a general semiconductor integrated circuit device, a resistance element is constructed of a diffused resistor using a base diffusion region, and its resistance temperature characteristic is approximately 1000 to 2000 p p m /'I
G, it is common to design a circuit such that the resistance value is not affected by changes due to temperature tL. However, in a circuit that uses the resistance value itself.

It is impossible to create an e-meter that cancels out changes in resistance based on the ff1 degree characteristic. for example,#! An example is a delay circuit whose delay time is determined by the values of resistance and capacitance. 1 and 2 are circuit diagrams showing examples of conventional delay circuits.

In the figure, (1) is an input terminal, (2) is an output terminal, and R
, R' represent resistance, and C represents capacitance. It is known that in these delay circuits, the delay time is determined by 2CR. Therefore, as the resistance value changes with temperature, the delay time changes and is directly affected by the resistance temperature characteristics.

The main object of the present invention is to substantially eliminate the resistance temperature change of the circuit (by maintaining the temperature inside the chip constant) in a semiconductor integrated circuit device including a circuit affected by such resistance temperature characteristics. That is. This invention will be specifically explained below with reference to one drawing.

FIG. 3 is a circuit diagram showing an embodiment of the present invention.

In Fig. K, the part surrounded by a dotted line indicates the same tip (or bullet), and parts corresponding to W41 and Fig. 2 are given the same reference numerals. Rf is an external resistance added to the outside of the chip and serves as a reference for temperature control. For the external resistor R1, choose a resistor with little resistance temperature change, such as a metal oxide film resistor. (4) is a ratio I2 circuit, (5) is a temperature control circuit, and (6) is a delay circuit.

The comparison circuit (4) is a circuit that compares the resistance values of the external resistance Rf and the internal diffusion resistance W. Now, assuming that the resistance values of the external resistor R4 and the internal diffused resistor are equal, the collector currents of transistors Q1 and Q2 are equal, and the transistor Qa
, Q4's collector currents are also approximately equal.

At this time, the voltage appearing at the output terminal (3)K of the comparison circuit (4) is low, and almost no current flows through the base of the transistor of the temperature control circuit (5), and no collector current flows either.

Therefore, the temperature control circuit (5) does not increase the temperature inside the chip.

However, if the resistance value of the internally diffused resistor W becomes smaller than the external resistor Rf, the collector current of the transistor Q2 increases and the collector current of the transistor Q2 decreases. Therefore, the voltage at the output terminal (3) increases, current flows into the base of the transistor of the temperature control circuit (5), and thus a collector current begins to flow, increasing the temperature within the chip. This temperature increase continues until the resistance value of the internal diffusion resistance W gradually increases and becomes equal to the external resistance Rf, and stops at the 9th point in time when the resistance value becomes equal. From this state, if the resistance value of the internal diffused resistor becomes larger than the external resistor R, the collector current of transistor Q2 will decrease and the collector current of transistor Q4 will increase, so the voltage at the output terminal (3) will further decrease. Therefore, the temperature control circuit (5) does not operate, and the temperature inside the chip does not rise but falls due to natural cooling.

In other words, the comparison circuit (4) compares the resistance values of the external resistance fLr and the internal diffusion resistance and generates an output that compensates for the difference in resistance value, but the temperature control circuit (5) compares the resistance values of the external resistance fLr and the internal diffusion resistance. Since the temperature inside the chip is controlled so that both resistance values are always equal, the temperature inside the chip is maintained constant at the temperature when both resistance values are equal. Since the circuit (5) cannot forcibly lower the temperature inside the chip, the above-mentioned constant temperature is set to a sufficiently high temperature in consideration of the outside air temperature, the amount of heat generated inside the chip, and the like.

This set temperature can be freely selected by increasing the resistance value of the external resistor Rf relative to the resistance value of the internal diffusion resistor and changing that value.

When the temperature inside the chip is maintained constant in this manner, the delay time 20R of the delay circuit (6) is maintained constant regardless of its resistance temperature characteristics. In other words, the circuit inside the chip is
This results in a state where there is virtually no change in resistance temperature, not only in delay circuits.

Incidentally, since it is inevitable that the resistance value of the diffused resistor within a chip will vary due to manufacturing, the above-mentioned set temperature will vary somewhat from chip to chip due to this variation.

#I4 Diagram 4 shows the operating situation in this case, so the vertical axis shows the resistance value and the horizontal axis shows the internal temperature of the chip.In the diagram,
A, B, and C are resistance-temperature characteristic curves of three types of internally diffused resistors representing manufacturing variations, T is outside temperature, rA, I
Brc is the resistance value of each internally diffused resistor at outside temperature *TK*-, and f is the resistance value of external resistor R/.As mentioned above, the resistance value of internally diffused resistor W is equal to external resistor R7. Since the temperature rises at the stage, the outside temperature j [TK and the resistance value is rA, the temperature is at rA stage, and is the same (for rB, the temperature rises to TB, and for the same < tc, the temperature rises to [TC]). Even if the set temperature fluctuates due to manufacturing variations, the slow I11 circuit (6)
Since the resistance hole also has the same temperature characteristics as the resistance W, the resistance value of the resistance hole is maintained at a predetermined value.

Further, in the above embodiment, only the case where the temperature inside the chip is constant and the delay time 2CR of the delay circuit (6) is constant is explained, but in this case, in order to set the delay time 20R to a desired value, The resistance tag must be set so that it has a predetermined resistance fiL'1 at a constant temperature. The delay time determined in this way does not change unless the temperature inside the chip changes. However, in the present invention, the temperature inside the step can be easily changed by making the external resistance V variable, so the delay time of the delay circuit (6) in the integrated circuit is It becomes possible to change the outside easily.

As explained above, 1. According to the present invention, in a semiconductor integrated circuit device including a circuit that is affected by resistance temperature characteristics,
By keeping the temperature inside the chip constant, it is possible to substantially eliminate the resistance temperature change of the above circuit, and by changing the constant temperature inside the chip, the circuit constants of the above circuit (for example, delay time 2CR, etc.) can be reduced. ) can be changed.

It goes without saying that the present invention is not limited to the embodiments described above, and that various modifications and changes can be made without departing from the gist of the claims.

[Brief explanation of drawings]

Figures 1 and 2 are circuit diagrams showing conventional examples of delay circuits.
The figure is a circuit diagram showing an embodiment of the present invention, and FIG. 4 is an explanatory diagram of its operation. Rf...external resistance, W...chip diffused resistance, (4)...comparison circuit, (5)...temperature control circuit.

Claims (1)

[Claims] 9. A semiconductor integrated circuit device comprising: a circuit for comparing the resistance values of an external resistor and a diffused resistor within the chip; and a temperature control circuit for controlling the internal temperature of the chip using the output of the comparison circuit.