JPH0252891B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a waveform shaping circuit suitable for a logic circuit composed of I ² L (Integrated Injection Logic) elements.

The waveform shaping circuit of the present invention has a structure formed by combining two monostable multivibrators made of I ² L elements that can be easily integrated into a semiconductor integrated circuit.
The present invention also relates to a waveform shaping circuit suitable for a logic circuit that can obtain output waveforms of individual monostable multivibrators and can also obtain an output waveform that is a combination of the pulse widths of the respective output waveforms.

The main object of the present invention is to provide a waveform shaping circuit comprising I ² L elements.

Another object is to provide a waveform shaping circuit consisting of a monostable multivibrator consisting of two I ² L elements.

Still another object is to provide a waveform shaping circuit that can obtain an output waveform that is a combination of the pulse widths of the respective output waveforms from two monostable multivibrators made of I ² L elements.

The waveform shaping circuit of the present invention is designed to achieve the above-mentioned objects, and details thereof will be explained below with reference to the drawings.

FIG. 1 is an explanatory diagram for explaining the outline of the waveform shaping circuit of the present invention. A and B are monostable multivibrators, 1 is the trigger pulse input terminal, 3 is the output terminal, 4 and 5 are capacitors for charging and discharging, T
is a transistor. When a trigger pulse is input to input terminal 1, monostable multivibrator A
Charging of the capacitor 4 starts and an output waveform is obtained. At the same time, the transistor T turns on and prevents the capacitor 5 from starting to be charged.
When charging of the capacitor 4 is completed, the transistor T is turned off, charging of the capacitor 5 is started, and waveform shaping is performed. And output terminal 2
From this, a combined waveform of the output waveforms of monostable multivibrators A and B is obtained. Further, from the output terminal 3, a waveform obtained by adding the pulse widths of the output waveforms of the monostable multivibrators A and B is output.

Next, an embodiment of a waveform shaping circuit including an I ² L element according to the present invention will be described with reference to FIG. A is a monostable multivibrator formed by I ² L elements 8 to 13 and capacitor 4,
B is a monostable multivibrator formed from I ² L elements 15 to 20 and a capacitor 5. Input terminal 1 is connected via I ² L element 7 to input ends of I ² L elements 8 and 15, respectively, and signals are transmitted to monostable multivibrators A and B, respectively. In monostable multivibrator A, the output end of I ² L element 8 is connected to I ² L element 9.
is connected to the input terminal of I ² L element 13 and the output terminal of I ² L element 13.
One of the output terminals of element 9 is connected to the input terminal of I ² L element 13.
It is connected between the output terminals of the I ² L element 12. ^I2L element 9
The other output terminal of is connected to the input terminal of the I ² L element 10,
Its output terminal is connected to the input terminal of I ² L element 11.
One end of the capacitor 4 is connected to the output end of the I ² L element 11 and the input end of the I ² L element 12. Furthermore, the monostable multivibrator B has the same configuration as the monostable multivibrator. and,
To explain the characteristic connection of monostable multivibrators A and B, the output terminal of I ² L element 9 of monostable multivibrator A is connected via I ² L element 21,
It is connected to the connection point between the output end of the I ² L element 16 and the input end of the I ² L element 17 of the monostable multivibrator B. Further, the output terminal of the I ² L element 16 is connected to the input terminal of the I ² L element 22, one of the output terminals of the I ² L element 22 is connected to the output terminal 3, and the other output terminal is connected to the input terminal of the I ² L element 22. It is connected to the input end of element 14. And I ² L element 1
One of the output terminals of 0 is connected to the output terminal of the I ² L element 14 and also connected to the input terminal of the I ² L element 6,
The output end of the I ² L element 6 is connected to the output terminal 2.

Now, the operation of the waveform shaping circuit shown in FIG. 2 will be explained based on FIG. 4.

A trigger pulse a at L level as shown in ^FIG . ^I2L element 8
When an H-level trigger pulse is input to the input terminal of the I ² L element 9, the input terminal of the I 2 L element 9 becomes L level, and its output terminal becomes H level. And I ² L element 10
The output terminal of the I ^{2 L element 11 becomes L level, and the output terminal of I 2} L element 11 becomes H level. Also, the output terminal of I ² L element 9 is H
level, so the output terminal of the I ² L element 13 is set to the L level. Therefore, the output level of I ² L element 8 after the trigger pulse is input is L level, but since its output terminal is set to L level, the output from the output terminal of I ² L element 9 is It is maintained at H level. Then, the potential at point b of the capacitor 4 is inverted from L level to H level when trigger pulse a is input. That is, since the charge in the capacitor 4 is in a discharged state and the potential at point b at the output end of the I ² L element 11 is inverted to H level, the I ² L
The injector current of the element 12 flows into the capacitor 4 as a charging current, and the potential at point b rises to H level as shown in FIG. 4b. Then, the potential at the output terminal of I ² L element 12 becomes L level, and the output terminal of I ² L element 13 is inverted from L level to H level. Therefore, the output terminal of I ² L element 9, which was in the locked state, is inverted from H level to L level. As shown in FIG. 4c, the output waveform of the output terminal c of the I ² L element 9 has a pulse width corresponding to the charging time T ₁ of the capacitor 4. In addition, I ² L element 9
The output is input to the monostable multivibrator B via the I ² L element 21.

Next, monostable multivibrator B will be explained. Similar to monostable multivibrator A, when trigger pulse a is input to I ² L element 15 via I 2 L element 7, the output terminal of I ² L element 15 becomes L level, and the output terminal of I ² L element 16 becomes L level ^. Although the output terminal becomes H level,
Monostable multivibrator A sets one of the output terminals of I ² L element 16 to L level via I ² L element 21 . Therefore, the output terminal of I ² L element 17 becomes H level, and the output terminal of I ² L element 18 becomes L level. Further, since the other output terminal of I ² L element 16 is at H level, the output terminal of I ² L element 20 is set at L level, and I ² L element 16 is in a locked state. Since the output terminal of the I ² L element 18 is set to the L level, the potential at point d of the capacitor 5 is as follows.
The charge of the capacitor 5 is in a discharged state. And from monostable multivibrator A to I ² L element 2
When the level of the junction between I ² L elements 16 and 17 is changed from L level to H level through I ² L element 17,
The output level of the I ² L element 18 becomes L level, and the level of the output terminal of the I 2 L element 18, that is, the level of point d becomes H level, so the injector current of the I ² L element 19 flows into the capacitor 5 as a charging current, and the fourth As shown in Figure d, the potential at point d gradually rises to H level. Then, the output terminal of the I ² L element 19 becomes L level, and I ² L
The output terminal of element 20 becomes H level. Therefore,
The lock state of I ² L element 16 is released. and,
The output waveform of the I ² L element 22, that is, the output waveform of the output terminal 3, is generated at the same time as the trigger pulse a is input.
Since the output terminal of the I ² L element 16 is set and held at the H level, the output terminal of the I ² L element 22 is held at the L level for a period until the potential at point d of the capacitor 5 reaches the H level (the Figure 4 e). The period during which the output terminal of the I ² L element 22 is held at L level corresponds to the charging time (T ₁ +T ₂ ) of the capacitors 4 and 5 of the monostable multivibrators A and B. Output end of I ² L element 6,
That is, the output terminal 2 outputs the combined output waveform from the I ² L elements 22 and 14 and the I ² L element 10.
Then, the output terminal of the I ² L element 14 is at H level,
Since the I ² L element 10 is at the L level, the potential at the output terminal of the I ² L element 6 is determined by the I ² L element 10 (FIG. 4f).

Next, FIG. 5 shows another embodiment of the present invention.
A waveform shaping circuit consisting of I ² L elements will be explained.
The difference between the embodiments in FIG. 5 and FIG. 2 is that the I ² L element 21
In the embodiment of FIG. 2, the output terminal of I ² L element 1
6 and the input end of the I ² L element 17, whereas the embodiment of FIG. 5 is connected to the output end of the I ² L element 18. However, the operation shows the same output waveform as the operation waveform shown in FIG. 4, except that the levels at the input and output terminals of the I ² L elements 17 and 18 differ.

Incidentally, the I ² L elements 11 and 19 are involved in the discharge action of the capacitor 4 or 5, and in order to facilitate the discharge, the output end is connected to the multi-electrode 22 as shown in FIG.
By forming the capacitor 4, the discharge of the capacitor 4 can be facilitated.

In addition, from output terminal 3, L corresponding to the charging time (T ₁ + T ₂ ) of monostable multivibrators A and B is output.
It is clear that if another I ² L element is connected to the output terminal of the I ² L element 22, an H level output with a pulse width of (T ₁ + T ₂ ) time can be obtained. be.

Of course, in order for the output end of the I ² L element to maintain an L level output, it is clear that current must be drawn from the outside.

Furthermore, a waveform shaping circuit consisting of I ² L elements has the advantage that if the output end of any I ² L element is made into a multi-electrode, the output of that part can be easily taken out. Use in logic circuits such as waveform shaping circuits made of ^2L elements has the advantage that various functions can be formed by relatively simple circuits.

Note that FIG. 3a shows the symbol mark of the I ² L element, and FIG. 3 b shows the equivalent circuit of the I ² L element.

As mentioned above, the waveform shaping circuit comprising the I ² L element according to the present invention is formed of the first and second monostable multivibrators, and while the first monostable multivibrator is operating, the second monostable multivibrator is in operation. The monostable multivibrator is held in a locked state, and after the first monostable multivibrator has finished operating, the second monostable multivibrator is released from the locked state and operated, and the first and second monostable multivibrator are It is possible to easily obtain an output waveform with a pulse width that is a combination of the outputs of the multivibrators and the pulse widths of the output waveforms. It is also clear that the pulse width can be changed by changing the capacitance of the monostable multivibrator capacitor. In this way, relatively complex waveform shaping can be achieved with a simple circuit.

Furthermore, since the waveform shaping circuit of the present invention is formed from a monostable multivibrator consisting of I ² L elements, it can be easily formed as a semiconductor integrated circuit using the same bibolar process as other transistors and other elements. This has the advantage of providing an inexpensive circuit device.

In particular, the waveform shaping circuit of the present invention is formed from an I ² L element, two monostable multivibrators, and a second monostable multivibrator is formed by a first monostable multivibrator. The second monostable multivibrator starts operating after the first monostable multivibrator stops operating, and the pulse width can be arbitrarily set depending on the capacitance of the monostable multivibrator. It is characterized by being able to obtain an output with a combined pulse width. Also,
Despite being capable of complex pulse processing,
Another feature is that waveform shaping is possible with a relatively simple circuit. Additionally, since it can be formed by a bipolar process, it can be easily combined with other transistor circuits, and has the advantage of providing an inexpensive semiconductor integrated circuit device. Also,
If the waveform shaping circuit of the present invention is used in a logic circuit consisting of an I ² L circuit, versatility in pulse processing can be obtained.

[Brief explanation of drawings]

FIG. 1 is a diagram for explaining the outline of a waveform shaping circuit comprising an I ² L element according to the present invention, FIG. 2 is a circuit diagram showing an embodiment of the waveform shaping circuit of the present invention, and FIG. This is the symbol mark of the I ² L element, and is shown in Figure 3b.
is its equivalent circuit diagram, FIG. 4 is an operational diagram of the waveform shaping circuit of the present invention, FIG. 5 is a circuit diagram showing another embodiment of the waveform shaping circuit of the present invention, and FIG. 6 is a part of the circuit. It is a diagram. A, B: Monostable multivibrator, 4, 5:
Charge/discharge capacitor, 6-21: ^I2L element.

Claims (1)

[Claims] 1. A waveform shaping circuit including first and second monostable multivibrators, where the first and second monostable multivibrators are composed of an I ² L element and a capacitor whose charging current is an injector current. By simultaneously applying a trigger pulse to the first and second monostable multivibrators, charging of the first capacitor of the first monostable multivibrator by an injector current is started, Inverting the output of the first monostable multivibrator and blocking supply of charging current to the second capacitor of the second monostable multivibrator based on the inverted output of the first monostable multivibrator. Then, as the charging potential of the first capacitor rises, the first monostable multivibrator is inverted again to obtain a predetermined pulse width T ₁
When the output pulse of At the same time as obtaining an output pulse with a pulse width T ₂ , an output pulse with a pulse width (T ₁ +T ₂ ) obtained by combining the pulse widths of the output pulses obtained from the first and second monostable multivibrators is obtained. A waveform shaping circuit consisting of a characteristic I ² L element.