SU1242907A1 - Device for checking leakage current of complementary metal-oxide semiconductor integrated circuits in dynamic mode - Google Patents

Abstract

The invention relates to the control devices and the detection of an open defect in the microcircuits before they are installed in electronic devices. The purpose of the invention is to increase reliability. The device contains a source 1; power supply; busbars 2 and 3 for connecting a controlled chip, a capacitor 5, a comparator 6, a pulse width selector 7 and. the recording unit 8, containing the trigger 9 with the reset bus 10 and the indicator 11. Introducing new elements and forming new connections between the elements of the device makes it possible to detect leakage currents appearing in any combination of states of the connected triggers of the monitored object. 1 il. e 4 y

Description

This invention relates to instrumentation input controls and can be used in electronic circuits to control microcircuits.

The purpose of the invention is to increase the credibility of monitoring by detection. leakage currents appearing in any combination of the states of the connected triggers of the monitored object. :. The drawing shows a structural diagram of the device, explaining its operation.

The device contains a power source 1, two buses 2 and 3 for connecting a controlled chip, resis, torus 4, capacitor 5, comparator 6, selector. 7 pulse duration and registering unit 8, containing trigger 9 with reset bus 10 and indicator 11. Moreover, buses 2 and 3 are connected respectively to two outputs of power supply 1, the second input of which is connected by bus 3 through a resistor 4. First trigger input 9 is connected to output the selector 7 of the duration of the pulses, and the second input of the trigger 9 is connected: to the reset bus 10. Moreover, the capacitor 5 is connected in parallel to the resistor 4, and the bus 3 is connected to the input of the comparator 6.

The device works as follows.,

Before the start of control, the trigger 9 is reset by the signal on the reset bus 10 .. The monitored object (microcircuit) is connected to buses 2 and 3 and includes it in a dynamic mode of operation. .

If leakage currents are practically absent in the microcircuit, then current consumption occurs only at the moments of switching the microchip elements. Therefore, the current consumption during operation is impulsive. The shape of the current consumption pulses, depending on the state of the microcircuit triggers, can be triangular, trapezoidal, etc., and the base pulses can vary from d; oy periods of the clock of the master oscillator to the value of equal to their period. The repetition period of current consumption pulses is basically equal to half of the period of oscillations of cycles.

The current consumption of the chip (self-contained or as part of an electronic unit) in a static mode at

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the presence of leakage currents is direct current and appears only under certain conditions of the microcircuit triggers, and during its operation has the character of square-wave pulses with a duration and period determined according to the time constant state of those triggers in which are the leakage currents of the microcircuit, and the period of repetition of this state in the microcircuit, and the duration of the rectangular current consumption pulse is always longer than the period of the master oscillator. Therefore, with an appropriate choice of time, the resistor 4 - capacitor 5 is a variable component of the voltage on the bus 3, mainly due only to current pulses of a rectangular shape, i.e. current consumption controlled by the chip in a static mode.

When such a pulse appears on bus 3, the Comparator 6 is triggered and the signal from its output (the duration of this signal is actually equal to the duration of the signal at the input) is fed to the input, the selector 7 of the duration pulses, thanks to which the trigger 9 is generated The comparator 6 is only rectangular. Tie. caused by the presence of leakage currents.

If the microcircuit has a current consumption in a static retkim at a certain state of the microcircuit triggers, then the trigger 9 is activated and a signal appears on the indicator 11. In the absence of leakage currents, the trigger 9 remains in the initial state and the signal on the indicator 11 is not. is.

The proposed device provides detection of a latent defect in the microcircuits before they are installed in electronic devices and thereby enhances the objectivity of the control, leading to an increase in the reliability of electronic devices.

Claims (1)

Invention Formula The device for monitoring the leakage current of a CMOS chip in dynamic mode, containing a power source, a registering unit with a reset bus, and two buses for connecting a controlled / chip, respectively, to two 312429074 power supply outputs, the second you-registering unit is designed as the stroke of which is connected to the second bus indicator with the trigger, the first input through a resistor, different. which is connected to the output of the selector so that, in order to increase the pulse duration, and the second input Toburnness control by detecting a thrigger is connected to the dumping bus, NIN of the currents, leakage, it is equipped with the end of which the capacitor is connected with a paraldensatyr and a circuit from a series resistor, and the second bus connected to the comparator and selector is connected to the input of the pulse width comp.