JPS6135628B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to an integrated circuit device.

Recently, there has been a demand for higher speed and lower power consumption of integrated circuits, and as a result, smaller logic amplitudes are being used. However, there is a tendency that the smaller the logic amplitude, the more unstable the circuit operation becomes. In particular, in a circuit that uses the potential drop due to a load in which a resistor and a nonlinear element such as a diode are connected in parallel as the output signal amplitude, and uses the potential difference with the reference voltage as the next stage drive voltage, the output signal amplitude and the reference voltage are Due to differences in temperature fluctuations, there is a possibility that when the temperature changes, the drive voltage decreases and circuit operation becomes unstable. Therefore, it is necessary to stabilize the circuit by always setting the reference voltage at the center of the signal amplitude even if the temperature changes.

SUMMARY OF THE INVENTION An object of the present invention is to provide an integrated circuit device that prevents deviation of a reference voltage from a median value due to temperature changes during reading of memory cells, etc., and provides stable circuit operation.

The integrated circuit device of the present invention has first and second loads including first and second transistors whose bases and collectors are alternately connected and a nonlinear element connected between the respective collectors and a signal line. a flip-flop consisting of a flip-flop element, the emitters of which are connected to the emitters of the first and second transistors, the collectors of which are connected to the respective output terminals, and the flip-flop is connected to a first power source via a load resistor; potential detection means including third and fourth transistors, an emitter connected to a second power source, a base connected to the second power source via a first resistor, and a collector connected to the second power source via the second resistor. a fifth transistor connected to the first power supply and an emitter connected to the base of the first transistor via a third resistor; the base is connected to the collector of the first transistor; and the collector is connected to the first power supply. a power supply circuit comprising a sixth transistor connected to the sixth transistor; an emitter connected to the second power supply via a fourth resistor and a base connected to the emitter of the sixth transistor;
a reference potential generation circuit including a seventh transistor whose collector is connected to the first power supply via a fifth resistor and supplies a reference potential to the bases of the third and fourth transistors; The temperature coefficient of the forward voltage of the nonlinear element and the base-emitter voltage of the fifth transistor are adjusted such that the temperature fluctuation of the reference potential and the temperature fluctuation of the potential drop due to the first and second loads are at a predetermined ratio. temperature coefficients are set to be approximately equal, and a ratio of the product of the resistance values of the first and fourth resistors to the product of the resistance values of the third and fifth resistors is determined. do.

FIG. 1 shows a memory read circuit according to an embodiment of the present invention. Transistors Q ₁ and Q ₂ constitute a flip-flop, and use resistor R ₁ and diode D ₁ and resistor R ₂ and diode D ₂ connected in parallel as loads. A reference voltage generation circuit for detecting information stored in a memory cell is composed of transistors Q ₃ to Q ₁₀ and resistors R ₃ to _{R 8} . Resistors R ₁₁ and R ₁₂ are output load resistances. The circuit 14 is a write input buffer circuit for sending a signal to the reference voltage generation circuit to make transistor Q ₉ conductive and transistors Q ₇ and Q ₈ non-conductive when reading information stored in the memory cell.
A power supply circuit composed of transistors Q ₁₁ , Q ₁₂ and resistors R ₉ , R ₁₀ , R ₁₃ drives a current source circuit including transistor Q ₁₀ and resistor R ₈ of the reference voltage generation circuit.

To read the memory of a memory cell, when the memory cell is selected by the address line 10, it is determined whether transistor Q ₁ or Q ₂ forming a flip-flop is conducting _.
It is detected by comparing the base potential of _Q4 and the base potential of transistor _Q1 or _Q2 , and the detected signal is obtained as an output by load resistors _R11 and _R12 . That is, when transistor Q ₁ is conductive and transistor Q ₂ is non-conductive, the current of constant current source Ib flows from transistor Q ₁ and the current of constant current source Ia flows from transistor Q ₄ . Therefore, transistor Q ₃ becomes non-conductive and transistor Q ₄ becomes conductive, and this current flows through load resistor R ₁₂ and is detected as an output voltage. At this time, the larger the potential drop due to the combined resistance of resistor R ₁ and diode D ₁ , the more stable the operation of the memory cell becomes, and the wider the variable range of the base potential of transistors Q ₃ and Q ₄ , which serve as the reference potential, and the larger the noise margin. Become. However, when the junction voltage of the diode _D1 becomes smaller due to a temperature change, the potential drop due to the combined resistance becomes smaller. If the reference potential is not affected by temperature changes at this time, there is a possibility that the reference potential will deviate from the median value of the amplitude of the combined resistance, causing malfunction. The present invention always sets the reference voltage to the median value of the signal voltage for signals whose potential changes due to temperature changes, so the power supply circuit that drives the current source circuit of the reference voltage generation circuit has appropriate temperature characteristics. It is characterized by having When the base-emitter voltage V _BE (Q ₁₂ ) of transistor Q ₁₂ in the power supply circuit and the base-emitter voltage V _BE (Q ₁₀ ) of transistor Q ₁₀ in the current source circuit are made equal, the voltage across resistor R ₈ is equal to resistor R It will be equal to the voltage across ₉ .
Also, the voltage V (R ₉ ) across the resistor R ₉ is
Base-emitter voltage V _BE (Q ₁₂ ) and resistance of Q ₁₂
The relationship between R ₉ and R ₁₀ is expressed by the following equation.

V (R ₉ ) = R ₉・V _BE (Q ₁₂ )/R ₁₀ (1) Therefore, the temperature fluctuation of V (R ₉ ) is the resistance ratio (R ₉ /R ₁₀ ) to the temperature fluctuation of V _BE (Q ₁₂ ). ) is obtained. Further, the voltage V(R ₇ ) across the resistor R ₇ that determines the reference voltage is V(R ₇ )=R ₇ ·V(R ₈ )/R ₈ (2). Therefore, the following equation can be obtained from equations (1) and (2).

V (R ₇ ) = R ₇ · V (R ₈ ) / R ₈ = R ₇ · V (R ₉ / R ₈ = R ₇ · R ₉ · V _BE (Q ₁₂ ) / R ₈ · R ₁₀ (3) Since the temperature fluctuation rate of all resistors is considered to be equal, the temperature fluctuation of the reference voltage is the temperature fluctuation of the base-emitter voltage of transistor _Q12 ΔV _BE (Q ₁₂ ) and the resistance ratio (R ₇ · R ₉ /R ₈ · R ₁₀ ) Determined by

Therefore, the temperature fluctuation of the signal on the side to be detected, that is, the temperature fluctuation of the junction voltage of diode D ₁ or D ₂ Δ
When V _D1 and ΔV _D2 are considered to be approximately equal to the temperature variation ΔV _BE (Q ₁₂ ) of the base-emitter voltage of transistor Q ₁₂ , the temperature variation on the reference voltage side is calculated by the resistance ratio (R By reducing ₇・R ₉ /R ₈・R ₁₀ ) to 1/2, it is possible to always set the reference voltage to the median value of the detection signal without being affected by temperature changes.

As described above, the present invention is very effective in stably reading data from memory cells and the like without being affected by temperature changes. Furthermore, the present invention can be widely applied to circuits other than memory read circuits.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing an embodiment of the present invention in the case of a read circuit for a semiconductor memory. In the figure, Q ₁ to Q ₁₂ ... transistors, R ₁ to
R ₁₃ ...resistor, D ₁ , D ₂ ... shotgun diode, Ia, Ib ... constant current source, V _EE ... constant voltage source.

Claims (1)

[Claims] 1 A flip-flop consisting of first and second transistors whose bases and collectors are alternately connected, and first and second load elements including nonlinear elements connected between their respective collectors and a signal line. and third and fourth transistors whose respective emitters are connected to the emitters of the first and second transistors, whose collectors are connected to the respective output terminals, and which are connected to the first power supply via a load resistor. A potential detection means including a transistor, and a second emitter.
a fifth transistor, whose base is connected to the second power source through the first resistor, whose collector is connected to the first power source through the second resistor, and whose emitter is connected to the third power source. is connected to the base of the fifth transistor via a resistor, the base is connected to the collector of the fifth transistor, and the collector is connected to the first transistor.
a power supply circuit consisting of a sixth transistor connected to the power supply of the sixth transistor; an emitter connected to the second power supply via a fourth resistor; a base connected to the emitter of the sixth transistor; and a collector connected to the sixth transistor. a reference potential generating circuit that includes a seventh transistor connected to the first power supply through a resistor No. 5, and supplies a reference potential to the bases of the third and fourth transistors; Temperature fluctuation and the first,
The temperature coefficient of the forward voltage of the nonlinear element and the temperature coefficient of the base-emitter voltage of the fifth transistor are set to be approximately equal so that the temperature variation of the potential drop due to the second load is at a predetermined ratio; The integrated circuit device is further characterized in that a ratio of the product of the resistance values of the first and fourth resistors to the product of the resistance values of the third and fifth resistors is determined.