KR900001227Y1 - Detecting circuit of hybrid i.c. operation - Google Patents

Abstract

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Description

Normal data communication measurement circuit of hybrid integrated circuit

1 is a data transmission circuit diagram.

2 is a block diagram according to the present invention.

3 is a detailed circuit diagram of an embodiment of FIG.

Figure 4 is a waveform diagram for explaining the operation of the present invention.

* Explanation of symbols for main parts of the drawings

10: low frequency oscillation circuit 20: frequency conversion circuit

30: frequency switching circuit 40: data transmission circuit

The present invention relates to a normal data communication measurement circuit of a data transmission circuit, and in particular, a data transmission circuit that hybridizes a data transmission circuit that receives an analog signal and converts it into a digital signal and receives and converts the digital signal into an analog signal. The present invention relates to a normal data communication measurement circuit of an integrated circuit.

1 is a hybrid integrated circuit of a data transmission circuit which converts an analog signal into a digital signal and converts the digital signal into an analog signal, and includes resistors R1-R13, capacitors C1-C5, diodes D1-D2, It consists of operational amplifiers (OP1-OP4).

The circuit is connected to the terminal pin 1 with a signal having a 6 ms high " high " high and 6 m sec " low " A sinusoidal wave having a period of 6.25KHZ 12msec is outputted to the terminal pin 2 by a multi-feedback bandpass filter oscillator circuit consisting of R1-R3 and R14, a capacitor C1-C2, and an operational amplifier OP1.

At this time, the 12 msec signal in FIG. 4 (a) is a signal in which a sine wave signal of 6.25 KHZ is not loaded in the 6 msec " low " period in the 6 msec high period.

On the other hand, when a sine wave having a period of 6.25KHZ 12msec is output to the pin 2, the oscillation is performed by a multi-feedback bandpass filter oscillation circuit composed of a resistor (R4-R7), a capacitor (C3-C4), and an operational amplifier (OP2). The signal is inverted and amplified by an inverting amplifier circuit composed of resistors R8, diodes D1-D2, and operational amplifiers OP3.

The inverted-amplified signal is input as a comparison signal of a comparator circuit composed of resistors R10 to R13, a capacitor C5, and an operational amplifier OP4.

At this time, the voltage 5V is input to the terminal pin 4, which is divided by a reference voltage of a predetermined level by the resistors R9 and R11 and input to the operational amplifier OP4. Accordingly, the operational amplifier OP4 compares the input signal with the reference signal to output a square wave signal having a period of 12 msec, that is, 6 msec "high" and 6 msec "low".

The conventional circuit for measuring whether the data transmission circuit is normal or not is composed of an oscillation circuit and measured as a sine wave signal of 6.25 KHZ, but it is very difficult to obtain accurate measurement data of the data transmission circuit.

In other words, the signal for accurately measuring the data transmission circuit has a period of 12 msec having a "high" signal section of 6 msec period and a "low" signal section of 6 msec period, and a sinusoidal signal of 6.25 KHZ or a conventional measurement signal is simple 6.25 KHZ. The frequency of the continuous sinusoidal wave is a large error from the actual signal, so the measured data is not accurate.

Accordingly, an object of the present invention is to provide a circuit that accurately measures the function of a hybrid integrated circuit that receives an analog signal and converts it into a digital signal and converts the digital signal into an analog signal.

The present invention for achieving the above object is a low frequency signal generation circuit for generating and outputting a square wave signal of a constant period, a frequency conversion circuit for converting and outputting a predetermined frequency to a high frequency, and inputting the square wave signal and a high frequency of the predetermined period of the square wave A frequency switching circuit which switches according to a logic signal and outputs a high frequency by a square wave logic, and inputs a frequency output from the frequency switching circuit, converts the high frequency into a sine wave signal corresponding to a square wave period, and then measures the measured signal of the circuit under measurement. Characterized in that it comprises a data transmission circuit for outputting.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

2 is a block diagram according to the present invention, a low frequency generation circuit 10 for generating and outputting a square wave signal of a predetermined period, a frequency conversion circuit 20 for converting and outputting a constant frequency into a high frequency, and the low frequency signal generating circuit A frequency switching circuit for inputting a square wave signal of a predetermined period output from (10) and a high frequency output from the frequency conversion circuit 20 to perform a switching operation according to the logic signal of the square wave, thereby switching and outputting the high frequency by the logic of the square wave. And a data transmission circuit 40 for inputting the frequency output from the frequency switching circuit 30, converting it into a sine wave signal corresponding to a square wave period of high frequency, and outputting it as a measurement signal of the circuit under measurement.

Now, the low frequency signal generating circuit 10 generates square waves having the same constant period of 6 msec in each of the states of "high" and "low", and outputs them to the frequency switching circuit 30, which is constant in the frequency conversion circuit 20. When a high frequency of a period is generated and output to the frequency switching circuit 30, the frequency switching circuit 30 performs a switching operation according to the logic of the square wave frequency of the low frequency signal generation circuit 10 from the frequency conversion circuit 20. The generated high frequency is output to the data transmission circuit 40 by outputting a high frequency when the logic of the square wave is "high".

Therefore, the signal output from the frequency switching circuit 30, that is, the high frequency output from the frequency conversion circuit 20 is switched and output when the logic of the square wave signal output from the low frequency signal generation circuit 10 is "high". When the logic of the wave signal is "low", the high frequency output from the frequency conversion circuit 20 is interrupted. At this time, the data transmission circuit 40 inputs the high frequency switching output by the square wave of the low frequency period from the frequency switching circuit 30 converts the high frequency into a sine wave signal corresponding to the square wave period and converts it into a measurement signal of the circuit under measurement 50. Supply.

Therefore, when the circuit under test 50 that inputs the high frequency wave of the sine wave corresponding to the square wave period is normal, the square wave period signal output from the square wave oscillation circuit 10 is output to the output terminal pin 6.

3 is a detailed circuit diagram of one embodiment of the block diagram of FIG. 2, and includes resistors R1-R3, capacitors C1-C4, astable multivibrator 11, and monostable multivibrator. Low frequency signal generation circuit 10 composed of 12), frequency conversion circuit 10 composed of resistors R4, capacitors C5-C6, crystals X-Tal, and counters 21, A frequency switching circuit 30 composed of R5-R6, a transistor Q1, and an AND gate AND1, and a data transfer circuit 40 (data transfer circuit in FIG. 1).

Reference numeral 50 in the drawings indicates a data transmission circuit of FIG. 1 as a circuit to be measured.

4 is an operation waveform diagram for explaining the operation of the present invention.

The fourth (c) as the period T-0.693 [(R ₁ + 2R ₂ ) 2 · C1] by the resistors R1-R2 and capacitors C1 (C2) connected to the unstable multi-vibrator 11 now. The monostable multivibrator 12 is triggered at the low edge of the input signal when a square wave having the same period of 12 msec is generated and input to the trigger input terminal T of the monostable multivibrator 12. At this time, the monostable multivibrator 12 resistor R3 and capacitor C3 output a signal of a periodic 6 msec "high" square wave to the output terminal OUT as shown in the fourth (d) as shown in FIG. Output to transistor Q1 through R6).

Accordingly, the monostable multivibrator 12 outputs a signal having 6 msec high and 6 msec low as shown in FIG. 4 (d).

The transistor Q1 inputs a 6 msec " high " 6 msec " low " square wave output from the monostable multi-vibrator 12 as shown in FIG. 4 (d). By passing through the collector-emitter, the power supply Vcc input through the N-B is outputted to the input terminal (b) of the AND gate (AND1) by outputting a "low" signal as shown in FIG. 4 (e) and a "high" signal. Is input, it is " turned off " and outputs a " high " signal as shown in FIG. 4E to the input terminal b of the AND gate AND1.

On the other hand, the counter 21 divides the high frequency oscillation signal (about 800KHZ) by the crystal (X-TaI), the capacitor (C5-C6), and the resistor (R4) connected to the oscillation input terminal (OSC IN) for 7 minutes. b) The continuous square wave of 6.25KHZ as shown in the figure is outputted to the output terminal Q7, and the input terminal a of the AND gate AND1 is output.

Therefore, the counter 21 in the frequency conversion circuit 20 divides a square wave signal of a high frequency (about 800KHZ) oscillated by the crystal (X-taI), the capacitor (C5-C6), and the resistor (R4) to about 6.25. The output is converted to the frequency of KHZ.

The AND gate AND1, which inputs the signal " low " to the terminal b by " turning on " of the transistor Q1, has a high frequency of 6.25KHZ outputted from the counter 21 as shown in FIG. 4 (b). Input as (a) to output the "low" signal.

On the other hand, when the monostable multivibrator 12 outputs a 6msec signal of "low", as described above, the transistor Q1 is "turned off" and the "high" signal is input to the input terminal b of the AND gate AND1. When inputted, the frequency of 6.25KHZ outputted from the counter 21 and the "high" signal are logically multiplied to output the frequency of 6.25KHZ to the terminal pin 1 of the data transmission circuit 40 for 6msec.

Therefore, the signal output from the AND gate AND1 is 6msec " high " high " 6msec " low " signal and the 6.25KHZ signal output from the counter 21 are logically multiplied and output as shown in FIG. 4 (f). It is input through pin (1) of (40).

Therefore, 6.25 KHZ is output from the AND gate AND1 for 6 msec, and no signal is output for the remaining 6 msec.

On the other hand, the data transmission circuit 40 inputs the signal output as described above in the AND gate AND1 and outputs the high frequency square wave signal of 6.25KHZ which is included for 6 msec of 12 msec as shown in the fourth (f). As shown in the figure, the signal is converted into a 6.25KHZ sine wave and output as a measurement signal having a 6.25KHZ sine wave signal for 6msec of the 12msec period to pin (2) of the circuit under test 50 which is the data transmission circuit of FIG.

At this time, if the measured circuit 50 that inputs the sine wave signal of 6.25KHZ period output from the data transmission circuit 40 for 6msec outputs the square wave of 6msec high 6msec period to the output terminal pin 6, the circuit under test (50) is normal and abnormal when other signals are output.

As described above, the present invention is a simple circuit that can accurately measure a data transmission circuit that changes and transmits an analog signal as a digital signal and a digital signal as an analog signal. This improves reliability while simultaneously finding a large quantity of products in the shortest possible time.

Claims (1)

A normal data communication measurement circuit of a circuit under test 50 for converting an analog signal into a digital signal and converting the digital signal into an analog signal, wherein the low frequency signal generation circuit generates a low frequency square wave signal and outputs it as a frequency switching signal. 10, a frequency conversion circuit 20 for converting and outputting a constant frequency into high frequency, a frequency switching signal of a square wave output from the low frequency signal generation circuit 10 and a high frequency output from the frequency conversion circuit 20 are inputted. To perform the switching operation according to the frequency switching signal, and to output the high frequency frequency for half (1/2) period of the input square wave and the sine wave signal of the high frequency switching output from the frequency switching circuit 30. And a data transmission circuit (40) for outputting the measured signal of the circuit under test (50).