CN111398783A - Digital IC rapid fault detection method based on 'foot' lines - Google Patents

Abstract

The invention belongs to the technical field of electronic information and discloses a digital IC rapid fault detection method based on 'foot' lines. The invention can find out the fault pin of the fault IC in the shortest time by using only one digital multimeter and one group of data meters collected by the digital multimeter without an external power supply, even if more than one pin is in fault, thereby carrying out fault judgment on the tested IC. The detection time is much shorter than the comprehensive detection time of an oscilloscope, a frequency spectrograph, a circuit board fault detector and the like. The method has simple and easy detection means and high detection efficiency, and is beneficial to marketization application.

Description

Digital IC rapid fault detection method based on 'foot' lines

Technical Field

The invention belongs to the technical field of electronic information, and relates to a rapid fault detection method based on 'foot' lines.

Background

Fault diagnosis is an indispensable important link in the technical field of electronic information. For fault diagnosis of a digital integrated circuit (hereinafter abbreviated as digital IC), besides the traditional fault diagnosis methods of measuring pin voltage, current, resistance to ground, and measuring signal waveform, frequency spectrum, etc., a special or universal circuit board fault detector can be adopted, which is expensive, and is rarely purchased and used by a plurality of common users, and only a unit such as a manufacturer, etc. which can produce great economic benefit through batch testing, can purchase a special circuit board fault detector.

For thousands of scattered individual users, oscilloscopes, spectrometer diagnosis and special circuit board fault detectors are adopted to solve the problem of integrated circuit fault diagnosis of electronic information technology equipment distributed in various places, but the problem is difficult to solve because the equipment is large in size, heavy in weight, expensive in price, low in efficiency due to long time consumption and the like, although digital ICs are effective. The traditional diagnosis methods not only have high equipment cost, but also have low diagnosis efficiency.

Disclosure of Invention

The invention aims to solve the problem of rapid fault detection of pins such as TT L74/54 series, CMOS40/45 series, 74L S373, 74L S245, 8031/51, 8096/98, 8086/8088, 8255/8237, ROM/EPROM/RAM and the like, and designs an efficient and convenient data acquisition method.

The invention can judge the fault of the tested IC by using only one digital multimeter and one group of data meters collected by the digital multimeter without an external power supply. For an IC, the decision to replace the IC can be made as long as a pin is found to be faulty.

The technical scheme of the invention is as follows:

a digital IC rapid fault detection method based on 'foot' lines comprises the following steps:

step 1, measuring a data table A of a standard normal integrated circuit;

1-1, adjusting a digital multimeter to a diode test gear;

1-2, setting the number of integrated circuit pins as N, and connecting a digital multimeter red pen to a grounding pin of the integrated circuit under the condition of no external power supply, wherein the number of other pins is N-1;

1-3, respectively connecting the black list pen to other N-1 pins, and collecting and recording the N-1 data; obtaining a data table A of a standard integrated circuit;

step 2, measuring a data table B of the integrated circuit to be detected;

pins of the integrated circuit to be detected correspond to pins of the standard integrated circuit in the step 1 one by one, and the measurement mode is the same as the method of 1-1 to 1-3 in the step 1, so that a data table B of the integrated circuit to be detected with a fault is obtained;

step 3, judging a fault state;

and judging four types of pin fault states according to the data change of the data table B relative to the data table A:

first, short-to-ground: if the data of the pin m is changed and the value in the data table B is changed to 0, the pin m is judged to be short-circuited to the ground;

second, open circuit: if the data of the pin n is changed and the value in the data table B is changed to 1, the pin n is judged to be open-circuited;

third, aging: if the data of the pin o is changed and is larger or smaller than the numerical value in the data table A, and the numerical value is neither 0 nor 1, judging that the pin o is aged;

fourth, short or lap connections between pins: and in the remaining N-1 pin data except the grounding pin, more than two pin data are smaller than the numerical values in the data table A, are equal and are not 0 or 1, and the corresponding pins are judged to be in short connection or lap connection.

The invention has the beneficial effects that: the fault pins of the fault IC can be found out in the shortest time by using the digital multimeter without an external power supply, even if more than one pin has a fault. The detection time is much shorter than the comprehensive detection time of an oscilloscope, a frequency spectrograph, a circuit board fault detector and the like. The method has simple and easy detection means and high detection efficiency, and is beneficial to marketization application.

Drawings

Fig. 1 is a flow chart of fast fault detection of a digital IC based on "foot" print in embodiment 1 of the present invention.

Detailed Description

The invention is further illustrated by the following figures and examples.

Example 1

Taking 54L S04 as an example, the basic "pin" pattern data is collected before the fault, shorting the pin to ground with a voltage breakdown.

1, standard normal IC state data acquisition:

(1) adjusting the digital multimeter to a diode test file;

(2) connecting a digital multimeter red meter pen to a grounding pin of the IC;

(3) if the number of IC pins is 14, the number of other pins is 13;

(4) the other 13 pins were connected with a black-pen, and the 13 data were collected and recorded.

2, collecting fault IC state data:

(1) adjusting the digital multimeter to a diode test file;

(2) connecting a digital multimeter red meter pen to a grounding pin of the IC;

(3) if the number of the fault IC pins is 14, the number of other pins is 13;

(4) the other 13 pins were connected with a black-pen, and the 13 data were collected and recorded.

Table 154L S04 six inverter (NOT gate) circuit footprint data Profile

3. Data diagnosis and results:

comparing the data in the 2 nd row and the 3 rd row, finding that the data in the 11 th leg is changed from 744 to 0, so that the conclusion is reached:

(1) the integrated circuit is damaged and is replaced immediately;

(2) the integrated circuit pin 11 is short-circuited to ground.

Example 2

Taking 54L S04 as an example, the basic "pin" pattern data is collected before the fault, shorting the pin to ground with a voltage breakdown.

1, standard normal IC state data acquisition:

(1) adjusting the digital multimeter to a diode test file;

(2) connecting a digital multimeter red meter pen to a grounding pin of the IC;

(3) if the number of IC pins is 14, the number of other pins is 13;

(4) the other 13 pins were connected with a black-pen, and the 13 data were collected and recorded.

2, collecting fault IC state data:

(1) adjusting the digital multimeter to a diode test file;

(2) connecting a digital multimeter red meter pen to a grounding pin of the IC;

(3) if the number of the fault IC pins is 14, the number of other pins is 13;

(4) the other 13 pins were connected with a black-pen, and the 13 data were collected and recorded.

Table 254L S04 six inverter (NOT gate) circuit footprint data Profile

3. Data diagnosis and results:

comparing the data in row 2 and row 3, finding that the data in the 9 th pin is changed from 751 to 1, so it is concluded that:

(1) the integrated circuit is damaged and is replaced immediately;

(2) the integrated circuit pin 9 is open.

Example 3

Taking 54L S04 as an example, the basic "pin" pattern data is collected before the fault, shorting the pin to ground with a voltage breakdown.

1, standard normal IC state data acquisition:

(1) adjusting the digital multimeter to a diode test file;

(2) connecting a digital multimeter red meter pen to a grounding pin of the IC;

(3) if the number of IC pins is 14, the number of other pins is 13;

(4) the other 13 pins were connected with a black-pen, and the 13 data were collected and recorded.

2, collecting fault IC state data:

(1) adjusting the digital multimeter to a diode test file;

(2) connecting a digital multimeter red meter pen to a grounding pin of the IC;

(3) if the number of the fault IC pins is 14, the number of other pins is 13;

(4) the other 13 pins were connected with a black-pen, and the 13 data were collected and recorded.

Table 354L S04 six inverter (NOT gate) circuit footprint data Profile

3. Data diagnosis and results:

comparing the data in row 2 and row 3, finding that the data in leg 6 is changed from 723 to 544, so we conclude that:

(1) the integrated circuit ages, suggesting replacement;

(2) the integrated circuit pin 6 ages.

Example 4

Taking 54L S04 as an example, the basic "pin" pattern data is collected before the fault, shorting the pin to ground with a voltage breakdown.

1, standard normal IC state data acquisition:

(1) adjusting the digital multimeter to a diode test file;

(2) connecting a digital multimeter red meter pen to a grounding pin of the IC;

(3) if the number of IC pins is 14, the number of other pins is 13;

(4) the other 13 pins were connected with a black-pen, and the 13 data were collected and recorded.

2, collecting fault IC state data:

(1) adjusting the digital multimeter to a diode test file;

(2) connecting a digital multimeter red meter pen to a grounding pin of the IC;

(3) if the number of the fault IC pins is 14, the number of other pins is 13;

(4) the other 13 pins were connected with a black-pen, and the 13 data were collected and recorded.

TABLE 454L S04 six inverter (NOT gate) Circuit footprint data Profile

3. Data diagnosis and results:

comparing the data in the 2 nd row and the 3 rd row, finding out that the data in the 3 rd foot and the data in the 11 th foot are not equal to the normal value, neither is 1 or 0, and the two are equal, so as to draw a conclusion:

(1) the integrated circuit is damaged and is replaced immediately;

(2) the integrated circuit pin 3 and pin 13 are shorted or shorted.

For the detected digital IC, the time for detecting each pin is 1 second, the time for completing the measurement of 14 pins is at most 14 seconds, and the measurement of a grounding pin is not needed. From the collected basic footprint data, it is diagnosed within a maximum of 14 seconds, and like the 11-pin breakdown short to ground in this example, the ic fault is detected within 11 seconds. If the method of voltage, current, waveform, logic analysis and the like is adopted, 5-10 minutes or longer is usually required.

Therefore, the method for rapidly detecting the IC 'foot' lines is simple, has very high important value and extremely high detection efficiency. Has higher commercial value in field maintenance service. The method for rapidly detecting the pin lines of the IC is also suitable for data acquisition and detection of the pins of the module or the board card.

Claims (1)

1. A digital IC rapid fault detection method based on 'foot' lines is characterized by comprising the following steps:

step 1, measuring a data table A of a standard normal integrated circuit;

1-1, adjusting a digital multimeter to a diode test gear;

1-2, setting the number of integrated circuit pins as N, and connecting a digital multimeter red pen to a grounding pin of the integrated circuit under the condition of no external power supply, wherein the number of other pins is N-1;

1-3, respectively connecting the black list pen to other N-1 pins, and collecting and recording the N-1 data; obtaining a data table A of a standard integrated circuit;

step 2, measuring a data table B of the integrated circuit to be detected;

pins of the integrated circuit to be detected correspond to pins of the standard integrated circuit in the step 1 one by one, and the measurement mode is the same as the method of 1-1 to 1-3 in the step 1, so that a data table B of the integrated circuit to be detected with a fault is obtained;

step 3, judging a fault state;

and judging four types of pin fault states according to the data change of the data table B relative to the data table A:

first, short-to-ground: if the data of the pin m is changed and the value in the data table B is changed to 0, the pin m is judged to be short-circuited to the ground;

second, open circuit: if the data of the pin n is changed and the value in the data table B is changed to 1, the pin n is judged to be open-circuited;

third, aging: if the data of the pin o is changed and is larger or smaller than the numerical value in the data table A, and the numerical value is neither 0 nor 1, judging that the pin o is aged;

fourth, short or lap connections between pins: and in the remaining N-1 pin data except the grounding pin, more than two pin data are smaller than the numerical values in the data table A, are equal and are not 0 or 1, and the corresponding pins are judged to be in short connection or lap connection.

Images