JPH0357320A - Frequency division circuit device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention requires that the division frequency n can be freely selected depending on the input DC voltage value, and that a digital signal, such as a clock, is divided. This invention relates to a frequency dividing circuit VT arrangement applicable to various types of machinery.

[Conventional technology]

As is well known, a l/2n frequency divider circuit can be created by applying a trigger pulse with a period slightly faster than the inherent oscillation frequency of the astable multivibrator.

The conventional frequency divider circuit device shown in FIG.
7) and the synchronous input terminal (
II) If you want to divide the input frequency Cf> by f/2n, determine the constant t! so that the cut-off time of transistors (Q3) (Q4) becomes 2(n-1)/f.
: It is configured so that a frequency-divided output can be obtained at the s output terminal r (12).

[Problem to be solved by the invention]

death. However, in a circuit with such a conventional configuration, it is necessary to generate a trigger pulse with high precision.-11 The peripheral circuits of the transistors in the unstable multivibrator are also set with constants that carefully take into account the operating time. There is a problem that settings are required and the degree of freedom in frequency division selection is very narrow.

The present invention was made to solve these problems, and provides a frequency divider circuit device that allows the frequency division value n to be freely set as an integer value simply by changing the voltage value of the DC power supply. The purpose is to provide

[Means to solve the problem]

In order to achieve such an object, the frequency dividing circuit device of the present invention includes a DC/DC converter circuit including a switching element, a smoothing circuit section, a comparator, and a reference voltage circuit section, and a terminal load DC'':Ii pressure feedback. Sok, .1-
JJ: The output terminal of the semi-electric circuit is connected to the reference input terminal of the comparator, and the non-stable multi-vibrator circuit is connected to the non-stable multi-vibrator circuit. The oscillation output of the circuit is connected to the comparison input terminal of the comparator, and the output terminal of the comparator is connected to the control terminal of the switching element. The present invention is characterized in that it is configured to generate a constant voltage DC output, and is configured to obtain a frequency-divided output of the oscillation output of the astable multivibrator circuit from the free force terminal of the switching element.

[For production]

With the above configuration, the present invention drives the DC/DC converter circuit using an unstable multivibrator. In other words, since the DC/DC converter circuit has a function of keeping the output voltage constant, the DC/DC
When the input voltage of the converter circuit is increased, the switching element cannot maintain the output voltage if it is synchronized with the unstable multi-by-layer circuit. Therefore, in reality, in order to maintain sufficient current output, the switching element does not necessarily synchronize all the pulses of the astable multivibrator circuit, and as a result, the operation of the switching element does not necessarily synchronize the oscillation pulses of the astable multivibrator circuit. The frequency is divided into 1/n.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail based on FIG. The frequency dividing circuit device according to this embodiment shown in FIG.
It is composed of a C/DC converter circuit (l), a filter circuit (2), and an unstable multivibrator circuit (3). In these circuits (i) to (3), (C
I) to (C9) are capacitors, (R1) to (R9) are resistors, (Ql) and (Q2) are transistors, (D) is a diode, and (T) is a transformer.

The DC/DC converter circuit (1) includes a switching transistor (4) as a switching element, a smoothing circuit section (5) consisting of a diode (D), a lance (T), and a capacitor (C4), and a converter (G). , a constant voltage element (7) as a reference voltage circuit section, and the unstable multivibrator circuit (3) includes a pair of transistors (Ql) (Q2), resistors (R5) to (R8), and a capacitor ( 08) ((.J), the output terminal of the constant voltage element (7) is connected to the reference input terminal of the comparator (B), and the oscillation output of the unstable multivibrator circuit (3) is connected to the comparator (G). ), and the output terminal of the comparator (6) is connected to the control terminal of the switching transistor (4), so that the DCIE pressure input of the switching transistor (4) receives the switching action and the smoothing circuit section (5 ) is configured to generate a constant voltage DC output to the terminating load (10).

The DC/DC converter circuit (1) is designed so that a constant output of 5V can be obtained at the DC output terminal (9) in response to an input voltage of 5.5V to 9V at the DC input terminal (8). However, the switching frequency of the switching transistor (4) is from 20 ktlz or less to 100 kFlz.
It is set to change up to.

In addition, the unstable multi-by-break circuit (3) provides feedback of the DC voltage of the terminal load (10) and the constant voltage element (7).
) is operated using the output voltage of 2.5V as a power source to obtain a pulse output with a frequency of 80kHz, and this pulse output is passed through a filter circuit (2) to a comparator (
By adding to 6), a switching transistor (4
) is configured to be driven at 80kHz.

With this configuration, when the input voltage of the DC input terminal (8) is lowered, the switching transistor (
If 4) is synchronized with the unstable multivibrator circuit (3), it will not be possible to maintain the output voltage. Therefore, in reality, since the switching transistor (4) maintains a constant current output, all tenopulses of the astable multivibrator circuit (3) are not necessarily synchronized, and as a result, the switching transistor (4) maintains a constant current output.
) operates to divide the oscillation pulse of the unstable multivibrator circuit (3) into I/n.

Table t shows this frequency division operation.

The reason why the switching transistor (4) in Table 1 operates as shown in item 2 is that the current cutoff time of the switching transistor (4) is constant (1 μs), and the terminating load (10)
is constant, so when the DC input voltage becomes less than 5.668V, the switching transistor (4) operates to reduce the number of current interruptions and keep the current flowing to the terminal load (10) constant.

Therefore, at the discrete voltage values shown in Table 1, a switching operation of rIII frequency division is performed, and a negative pulse signal of f/n frequency division is obtained from the output terminal (I1). At the same time, a constant voltage of 5V is obtained at the output terminal (9).

Incidentally, even if the filter circuit (2) is omitted, the frequency division operation can be performed, but in reality, the stability of the frequency division pulse of the output terminal (IN) against minute changes in the input voltage is increased. It is preferable to insert it inside.

〔Effect of the invention〕

As explained above, when using the frequency dividing circuit device of the present invention, a highly accurate synchronous signal generator is not required, and the design of the unstable multi-by-play evening path is designed considering only the oscillation frequency. Moreover, if you have a precise DC power supply, you can freely set the division value n as an integer simply by changing the voltage value, providing a frequency division circuit device that is extremely useful in terms of circuit design and equipment configuration. It has shown excellent results.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing a frequency dividing circuit device of the present invention, and FIG. 2 is a circuit diagram showing a conventional frequency dividing circuit device. (1)...DC/DC converter circuit, (3)...
Unstable multivibrator circuit, (4)... switching element, (5)... smoothing circuit section, (6)... comparator, (7)... reference voltage circuit section, (IO)...
・Terminal load, (11)... Output terminal of switching element. Figure 7-14 17 Tka Zuigo Figure 2

Claims (1)

[Claims] (1) A DC/DC converter circuit equipped with a switching element, a smoothing circuit section, a comparator, and a reference voltage circuit section, and an unstable multivibrator circuit that operates based on the feedback of the DC voltage of the terminal load and the reference voltage. The output terminal of the circuit section is connected to the reference input terminal of the comparator, the oscillation output of the astable multivibrator circuit is connected to the comparison input terminal of the comparator, and the output terminal of the comparator is connected to the control terminal of the switching element. The DC voltage input is configured to receive a switching action and generate a constant voltage DC output to the terminal load via the smoothing circuit section, and the divided output of the oscillation output of the astable multivibrator circuit is used as the output of the switching element. A frequency dividing circuit device characterized in that the frequency is obtained from a terminal.