JPS58218229A - Selecting circuit of delay time - Google Patents

Abstract

PURPOSE:To select an optional delay time through a small-sized device by providing one package with a delay circuit which delays an input signal by plural different delay times and a selecting circuit which selects and outputs one of its outputs. CONSTITUTION:A delay circuit 8 inputs an input signal from an input terminal 12 through a buffer gate 17 and supplies plural signals with different delay times to a multiplexer MX10 through signal lines 9. The MX10 selects and outputs one of the signals from the signal lines 9 to an output terminal 14 according to a signal from a selection signal input terminal 13. The selection signal is a signal with a logical level and the selection is extremely easy. The circuit 8, a gate 17, and the MX10 are provided to one package 11, and consequently the total number of terminals of the package is decreased and the package is reduced in size to select an optional delay time by the combination of logical levels of the signal lines 13.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Background of the Technology The present invention relates to a delay time providing circuit used for clock adjustment in information processing devices and other general circuits that require a wide range of signal delays, and particularly relates to The present invention relates to a delay time selection circuit that can select an arbitrary delay time from among delay times.

(2) Problems with the conventional technology In the conventional delay time imparting circuit, a delay line composed of an inductance-capacitor, etc., or a delay line 1 as shown in Fig. 1, and a buffer gate 2 for waveform shaping are packaged in the same package. A built-in delay circuit is well known.

For one input terminal 4, such a delay circuit
It is configured to provide multiple outputs 5 with different delay times, and when used, select an output terminal with an appropriate delay time and connect it to each device by short circuiting or using a changeover switch. It was done to connect to. However, in addition to the delay circuit package, this method requires space occupied by the short circuit package and the transfer switch, which runs counter to today's trend toward large-scale integration. Also, the number of input and output terminals of the delay circuit is
For example, in order to be able to select 8 types of delay times, a total of 11 terminals, including 8 output terminals, an input terminal, a ground terminal, and a power supply terminal, are required, and there is a limit to the miniaturization of the package itself. However, if one were to increase the number of selectable delay times, the number of output terminals would have to be increased, which would inevitably result in an increase in size. Also, the selection of delay time is
It was time-consuming to solder short circuits, etc., and it was inconvenient to adjust the equipment. The present invention eliminates these drawbacks, reduces the number of output terminals of the package, enables miniaturization, and allows for different delay times to be arbitrarily selected, and can be changed freely even after selection. A delay time selection circuit is provided.

(3) Structure of the Invention The structure of the present invention is as described in the claims, and comprises a delay circuit and a one-selection circuit mounted in the same package, and output from the delay circuit. The selection circuit selects one of the plurality of outputs according to a selection signal input from the outside and outputs it to the output terminal.

(4) Examples of the invention FIG. 2 shows two embodiments of the invention.

In the figure, 8 is a delay circuit, 9 is its output signal line, and in this example eight types of delay times can be selected. A multiplexer 1o selects one of the nine output signal lines and outputs it to the output terminal 14.

The selection is controlled by a signal from the select signal input terminal 13, and since the select signal is a logic level signal, the selection is extremely easy. The terminal 13 is 8 in this example.
In order to switch the signal output of a book, only three terminals are required, and the total number of terminals in the package 11 is one input terminal 12, one output terminal 14, one each of ground terminal 16 and power terminal 15. Since the number of terminals is greatly reduced compared to the conventional example shown in Figure 1, the entire package can be made smaller, and the output terminal can be selected quickly. Since short circuits and the like are not required, the actual mounting space can be further reduced.

(5) As described in detail of the invention, the delay time selection circuit of the present invention is extremely compact and does not require any other short circuit for delay time selection, so the mounting space is even smaller.゛The delay time can be set and changed as desired, and it is extremely easy to change, so it saves time and effort in adjusting equipment, and it is easy to attach to the circuit because there is no need to solder short circuits. There are many advantages such as:

[Brief explanation of drawings]

FIG. 1 is a diagram showing an example of a conventional delay circuit, and FIG. 2 is a diagram showing an embodiment of the present invention. 1...Delay line, 2...Buffer Kate, S...Package, 4.Song/input terminal, 5...Output terminal, 6... ...Power supply terminal, 7...Ground terminal, 8...Delay circuit, 9...Output signal line of music delay circuit, 10...Haruka...Multiplexer, 11... ···package,
12... Four input terminals, 13... Select signal input terminal, 14... Song/output terminal, 15... Power supply terminal, 16... Earth terminal, 17... ...Buffer Gate.

Claims (1)

[Claims] A delay circuit that applies a plurality of different delay times to an input signal input from an input terminal and outputs the same, and a selection circuit that selects one of the outputs of the plurality of delay circuits according to a selection signal and outputs it to the output terminal. Delay time selection circuit installed in the same package