RU2793145C1 - Device for determining the load capacity of microcircuits - Google Patents

Abstract

FIELD: measuring technology.

SUBSTANCE: invention relates to measuring technology. The device for determining the load capacity of microcircuits contains a microcircuit under test 1, a square-wave voltage generator 2, a working microcircuit 3, a voltmeter 4, the first reference voltage source 5, the first comparator 6, an AND element 7, a pulse counter 8, a switch 9, load elements 10 - 1…10 - k, the second reference voltage source 11, the second comparator 12, the current-voltage converter 13.

EFFECT: improving the accuracy and reliability of determining the load capacity of microcircuits.

1 cl, 1 dwg

Description

The invention relates to the field of microminiaturization and technology of electronic equipment and can be used to control the parameters of microcircuits during their production.

A known method for determining the load capacity of microcircuits (Frolkin V.T., Popov L.N. Pulse and digital devices: Textbook for universities. - M .: Radio and communication, 1992. - 336 p.: ill. - p. 127 ) associated with finding the largest number of inputs of logic elements that can be connected to the output of the tested microcircuit without degrading its parameters.

The disadvantages of devices that implement this method are the low accuracy and reliability of determining the load capacity.

Closest to the proposed invention is a device for determining the load capacity of microcircuits (patent for the invention of the Russian Federation No. 2613568, IPC G01R 31/28, publ. , load elements, commutator, AND element, comparator, pulse counter and reference voltage source.

The disadvantages of the device are the low accuracy and reliability of determining the load capacity.

The invention is based on the task of improving the accuracy and reliability of determining the load capacity of microcircuits.

This problem is solved in a device for determining the load capacity of microcircuits, which contains a square-wave voltage generator, a first reference voltage source, a first comparator, an AND element and a pulse counter connected in series, a working microcircuit, the input of which and the input terminal of the microcircuit under test are combined and connected to the output of a rectangular-wave generator. voltage, a voltmeter and a switch, the control inputs of which and the second input of the AND element are combined and connected to the output of the working microcircuit, the signal input of the voltmeter is connected to the output terminal of the microcircuit under test, and its output is connected to the second input of the first comparator, load elements, the input of each of which is connected to the output of the switch of the same name, according to the invention, a second reference voltage source and a second comparator, connected in series, are additionally introduced into it, a current-voltage converter, the input and output of the current circuit of which are connected respectively to the output terminal of the microcircuit under test and the signal input of the switch, the output of the current-voltage converter connected to the second input of the second comparator, the AND element is made three-input and its third input is connected to the output of the second comparator.

The drawing shows a block diagram of the proposed device.

The device contains a microcircuit under test 1, a square-wave generator 2, a working microcircuit 3, a voltmeter 4, the first reference voltage source 5, the first comparator 6, an AND element 7, a pulse counter 8, a switch 9, load elements 10 - 1 ... 10 - k, the second reference voltage source 11, second comparator 12 and current-voltage converter 13.

The first reference voltage source 5, the first comparator 6, the AND element 7 and the pulse counter 8, as well as the second reference voltage source 11 and the second comparator 12 are connected in series in the device. 1. The control inputs of the voltmeter 4 and the switch 9, as well as the second input of the element AND 7 are combined and connected to the output of the working microcircuit 3. The third input of the element And 7 is connected to the output of the second comparator 12. The signal input of the voltmeter 4 is connected to the output terminal of the tested microcircuit 1, and its output - to the second input of the first comparator 6. The input of each of the load elements 10-1 ... 10-k is connected to the output of the switch of the same name 9. The input and output of the current circuit of the current-voltage converter 13 are connected respectively to the output terminal of the tested microcircuit 1 and the signal switch input 9. The output of the current-voltage converter 13 is connected to the second input of the second comparator 12.

The device allows you to determine the load capacity of the tested microcircuit 1 by changing the high level (first mode) and by changing the low level (second mode) of its output voltage, also controlling its output current in both modes.

In accordance with the first mode, the device operates as follows. Rectangular voltage generator 2 generates the first pulse, which is simultaneously supplied to the inputs of identical test 1 and working 3 microcircuits. At the output of each of these microcircuits, a high-level pulse with the same duration is formed. The output signal of the microcircuit under test 1 is simultaneously fed to the signal input of the voltmeter 4 and the input of the current circuit of the current-voltage converter 13, and from the output of the current circuit to the signal input of the switch 9. The latter is made on the basis of a shift register and a set of analog switches. The output signal of the working microcircuit 3 is simultaneously supplied to the control inputs of the voltmeter 4 and switch 9, as well as the second input of the AND element 7.

With the arrival of the first high-level pulse at the control input of the switch 9, the latter connects its signal input (the output of the microcircuit under test 1 through the current circuit of the current-voltage converter 13) to the input of the first load element 10-1.

At the output of the voltmeter 4, during the entire period of the output signal of the working microcircuit 3, which coincides in time with the same period of the microcircuit under test 1, the voltage value of the high level of the output signal of the latter is maintained. The first comparator 6 compares the values of the output voltages of the voltmeter 4 and the first reference voltage source 5. The latter coincides with the minimum allowable high voltage value of the output signal of the tested microcircuit 1.

At the same time, at the output of the current-voltage converter 13, during the lifetime of the high-level output pulse of the tested microcircuit 1, a voltage value proportional to its output current is maintained. The second comparator 12 compares the output voltages of the current-voltage converter 13 and the second reference voltage source 11. The latter is proportional (with the same coefficient as in block 13) to the maximum allowable value of the output current of the tested microcircuit 1 when the high level of its output voltage changes.

In the case of using a serviceable microcircuit under test 1, loaded by the output with element 10 - 1, the following occurs:

1. The output voltage of the voltmeter 4 exceeds the output voltage of the first reference voltage source 5 and a logic "1" is formed at the output of the first comparator 6. It enters the first input of the element AND 7.

2. The output voltage of the current-to-voltage converter 13 does not exceed the output voltage of the second reference voltage source 11, and a logic "1" is formed at the output of the second comparator 12. It enters the third input of the element AND 7.

In the presence of logical "1" at the same time on the first and third inputs of the element And 7, a high-level pulse passes from its second input to the output. In this case, the pulse counter 8 captures the arrival at its input of the first logical "1". This means that the load capacity of the tested microcircuit 1 as a result of the first working cycle of its determination is a number not less than one.

If the microcircuit under test 1, loaded by the output with element 10-1, is faulty, then the following events occur (one of the two or both at the same time):

1. The output voltage of the voltmeter 4 does not exceed the output voltage of the first reference voltage source 5 and at the output of the first comparator 6 a logical "0" is formed. It enters the first input of the element AND 7.

2. The output voltage of the current-voltage converter 13 exceeds the output voltage of the second reference voltage source 11 and a logical "0" is formed at the output of the second comparator 12. It is fed to the third input of the AND element 7.

If there is a logical "0" on the first or third inputs of the element And 7 (or on both inputs simultaneously), the passage of a high-level pulse from its second input to the output is blocked. In this case, the pulse counter 8 stops counting.

During the subsequent output pulses of the square-wave generator 2 (in the first mode), the device as a whole operates in the same way as previously described. The only difference is that with the arrival of the next pulse (high level) to the control input of the switch 9, the latter connects its signal input to the input of the load element of the same name, from the available 10-2 ... 10-k. Each of them includes a number (from one to several tens) of identical logical elements, the number of inputs of which, combined with each other by a common input of the load element, coincides with its number. At the same time, with each new switching of the switch 9, the value of the voltage of the high level of the output signal of the tested microcircuit 1 (due to the drop in load resistance) decreases, and the value of its output current increases.

The pulse counter 8 captures the pulses during all work cycles, thereby recording the number (n) that determines the load capacity (in the first mode) until the following conditions are simultaneously met:

1. The output voltage of the voltmeter 4 exceeds the output voltage of the reference voltage source 5.

2. The output voltage of the current-voltage converter 13 does not exceed the output voltage of the second reference voltage source 11.

To ensure the second operating mode of the device, which allows determining the load capacity of the tested microcircuit 1 by changing the low level of its output voltage, it is necessary:

- connect the first input of the first comparator 6 to the output of the voltmeter 4, and the second input to the output of the reference voltage source 5,

- the value of the output voltage of the first reference voltage source 5 is set equal to the maximum allowable value of the voltage of the low level of the output signal of the tested microcircuit 1,

- set the value of the output voltage of the second reference voltage source 11 proportional (with the same coefficient as in block 13) to the maximum allowable value of the output current of the tested microcircuit 1 when the low level of its output voltage changes.

At the same time, with each new switching of the switch 9, the values of the low-level voltage and the current of the output signal of the tested microcircuit 1 increase. The pulse counter 8 captures the pulses during all work cycles, thereby recording the number (n) that determines the load capacity (in the second mode) until the following conditions are met:

1. The output voltage of the voltmeter 4 remains less than the output voltage of the reference voltage source 5.

2. The output voltage of the current-voltage converter 13 does not exceed the output voltage of the reference voltage source 11.

Otherwise, the operation of all units of the device in both modes is the same.

The introduction of the second reference voltage source 11, the second comparator 12, the current-voltage converter 13 and the implementation of the AND element as three-input made it possible to control the output current of the tested microcircuit 1. This made it possible to determine the load capacity (in two modes) not only by changing the output voltage, but also additionally by changing the output current of the tested microcircuit 1, while excluding its thermal breakdown.

Claims (1)

A device for determining the load capacity of microcircuits, containing a square-wave voltage generator, a first reference voltage source, a first comparator, an AND element and a pulse counter connected in series, a working microcircuit, the input of which and the input terminal of the microcircuit under test are combined and connected to the output of the rectangular voltage generator, a voltmeter and a switch , the control inputs of which and the second input of the AND element are combined and connected to the output of the working microcircuit, the signal input of the voltmeter is connected to the output terminal of the microcircuit under test, and its output to the second input of the first comparator, load elements, the input of each of which is connected to the output of the switch of the same name, which differs by the fact that a second reference voltage source and a second comparator, connected in series, a current-voltage converter, the input and output of the current circuit of which are connected respectively to the output terminal of the microcircuit under test and the signal input of the switch, are additionally introduced into it, the output of the current-voltage converter is connected to the second input of the second comparator, the AND element is made three-input and its third input is connected to the output of the second comparator.

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