JPH01311614A - Monostable multivibrator - Google Patents

Abstract

PURPOSE:To accurately obtain targeted output pulse width by deciding output pulse width based on a clock interval to be impressed on the clock input of a counter and the count value of the counter. CONSTITUTION:The title multivibrator is constituted of a D flipflop 1 with set, an n-bit counter 2 with the count value of N, and a NOR gate 3. And the flip-flop 1 is set by an input pulse 4, and the counter 2 is cleared and released by its output signal, and counting is started from a clock signal 5 arriving next, and at a time when (N+1) clock pulses are inputted, all logic '0's are outputted from the n-bit output (21-2n) of the counter 2. Therefore, the output of the NOR gate 3 goes to all logic '1's, and pulse output 6 goes to the logic '1' again, and an operation as a monostable multivibrator is performed on the input pulse. In such a way, it is possible to obtain arbitrary output pulse width with high accuracy by controlling the accuracy of the clock and a clock frequency.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a mono-multi-bibreak.

[Conventional technology]

Generally, a monomultivibrator is designed to apply an input pulse and then obtain an arbitrary defined output pulse width. Conventional monomultivibrators achieve this goal by setting a time constant based on the integral action of the pulses. That is, an integrating circuit consisting of one resistor and one capacitor is connected to a predetermined voltage source, for example, a power supply, from the time when an input pulse is applied, and is caused to integrate, and the time when the integrated voltage reaches a predetermined value is determined. It is designed to know the output pulse width during this period. Generally, mono-multivibrators are developed and commercially available as individual components and integrated circuits.

The configuration of this example is shown in FIG. In the example shown in the figure, the external resistor 8 and capacitor 9 are each selected, and a pulse of the desired pulse width is generated from the pulse output terminal 6 of the integrated mono-multivibrator 7 in relation to the time constant obtained by the product. get. Note that 4 is a pulse input terminal.

[Problem to be solved by the invention]

Conventional multivibrators rely on a time constant and voltage source to determine the output pulse width. This voltage source generally becomes the power supply voltage when the mono-multivibrator is integrated, so the output pulse width cannot be made variable by the voltage source.

Further, the values of the resistors and capacitors are generally fixed, and the output pulse width with respect to these values is also fixed. For this reason, it lacks flexibility in applications where a desired pulse width is obtained by external control. Furthermore, although the time constant is determined by each resistor and capacitor, it is not possible to accurately obtain the desired output pulse width due to variations in these.

[Means to solve the problem]

The mono-multivibrator of the present invention includes a set type flip-flop, an n-bit counter with a count value N, and an N-bit counter with a count value N.
an OR gate, a pulse input is connected to a set input of the flip-flop, an output of the flip-flop is connected to a clear input of the counter, an n visit output of the counter is an input of the NOR gate, and the NO
R, the output of the gate is connected to the clock input of the flip-flop, the output of the NOR gate is a pulse output, and the output pulse width is determined by the clock interval applied to the clock input of the counter and the count value N of the counter. The configuration is as follows.

[For production]

The mono-multivibrator of the present invention includes a set type flip-flop, an n-bit counter with a count value N, and an N-bit counter with a count value N.
It consists of an OR gate. The flip-flop is set by the pulse input, which is input to the clear terminal of the counter. As a result, the counter is cleared and starts counting from the next arriving clock pulse. When (N+1) clock pulses are input to the counter, the output of the NOR gate connected to the n-bit output of the counter changes from logic II O11 to logic ``1''. Connect the output of this NOR gate to the clock input of the flip-flop,
The data input of the flip-flop is connected to logic ``011''. After counting N as a result, the flip-flop output is reset.

If the output of this flip-flop is a pulse output, this output will have the function of a mono multivibrator.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a diagram showing an embodiment of the present invention. 1 is a flip-flop with a set, 2 is an n-bit counter with a count value N, 21 to 2n are counter output n-bit terminals, 3
4 is a NOR gate, 4 is a pulse input terminal for applying a pulse, 5 is a clock signal input terminal, and 6 is a pulse output terminal for obtaining an output pulse of the multivibrator.

Figure 2 shows the input pulse from the pulse input terminal 4 to a set type flip-flop 1 to explain the operation of Figure 1.
becomes the set input signal. Since the output signal of the set flip-flop 1 serves as a clear input signal for the counter 2, the counter 2 is cleared at this moment and starts counting from the next clock signal coming from the clock signal input terminal 5. When (N+1'') clock pulses are input, the n-bit output 21 of counter 2
~2n outputs all logic "0". Therefore, the output of NOR gate 3 which receives that signal as input is all logic.
1". As a result, the output of the pulse output terminal 6 becomes logic "1" again, and it operates as a mono multivibrator in response to the input pulse. This output is connected to the clock input terminal of the flip-flop 1. .The data input of flip-flop 1 is always given logic "0", and N.

At the rising edge of the output signal of the R gate 3, the flip-flop 1 reads the logic "'0". That is, it becomes a reset operation. As a result, the counter 2 becomes a clear state and stops the counting operation.

In the above-described operation, since the pulse input has the effect of being sampled by the clock signal, the pulse output has a width from (N-1) to N to be exact due to the sampling error. Here, when N is large, the error becomes small. In any case, the pulse output can be realized by controlling the clock frequency and selecting the number of stages of the counter instead of the time constant in the prior art.

〔Effect of the invention〕

As explained above, the present invention uses all logic circuits as a circuit configuration, eliminates analog values such as determining time constants and voltage sources using resistors and capacitors in the conventional technology, and instead converts them into more accurate digital values. It is based on the number of clocks (number of counter stages). Depending on the accuracy of this clock, how to give the clock frequency, etc., not only can an arbitrary time constant be given more precisely, but also the time constant can be changed flexibly simply by converting the clock frequency.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing one embodiment of the present invention, and FIG.
FIG. 3 is a diagram illustrating the operation of the conventional multivibrator. 1... Flip-flop with set, 2... n-bit counter, 3... NOR gate, 4... pulse input terminal, 5... tarokku signal input terminal, 6... pulse output terminal .

Claims (1)

[Claims] D-type flip-flop with set and n of count value N
a bit counter and a NOR gate, a pulse input is connected to a set input of the flip-flop, an output of the flip-flop is connected to a clear input of the counter, and an n-bit output of the counter is connected to an input of the NOR gate. and the output of the NOR gate is connected to the clock input of the flip-flop, the output of the NOR gate is a pulse output, and the output pulse width is applied to the clock input of the counter at a clock interval and a count value N of the counter. A mono multi-vibrator characterized by determining.