Abstract: In particular in automatic testing equipment for integrated circuits, all signal sections at the test piece joint should ideally be of the same electrical length. The signal sections used in the test consist, in the case of reception, of cable, comparator, error logic, etc. If the signal sections are of different electrical durations, then in the case of reception, the transmitted signal must be connected. In a process for determining the electrical duration of signal sections, each of which has a transmitter and a receiver and at the end connecting points for example for an integrated circuit, the connecting points (AS) of all signal sections (SS) are short-circuited, all receivers up to the receiver of the signal section to be measured are then switched off, all transmitters up to the transmitter of the signal section to be measured are switched on and simultaneously emit a pulse which is transmitted to the connecting point.

Abstract: For the purpose of testing units which contain electrical circuits, an interpretation circuit and a load circuit are connected to the output of the unit being tested by way of a line. A load circuit is provided which contains two constant current sources which are respectively variable in terms of current value and which are respectively connectible and disconnectible. The one constant current source therefore serves as a load current source and the three serves as a load current sink. A determination can be made, with the assistance of a variable control voltage, as to whether the load circuit operates as a current source or a current sink. The constant current source and the variable control voltage are connected to one another and to the line to the unit being tested by way of a diode bridge. A comparator circuit is connected to the same line and comprises an impedance and voltage level converter and two comparators. Separately variable reference voltages are supplied to the comparators.

Abstract: Test signals emitted by a test facility A may have a chronological offset relative to a defined time point which is unacceptable for certain units under test having a fast response circuitry. A system is inserted between the test facility and such a unit under test so as to provide a smaller chronological offset. This system contains a transmitter and a receiver connected in anti-parallel fashion with respect to one another. The transmitter connects the test signal of the test facility through to the unit under test as a test signal only when a clock signal and a change-over signal are present at the transmitter. The clock signal can be generated at a determinable point in time in a simple manner and thus the point in time of the appearance of the various test signals can be determined without a great offset from this point in time.

Abstract: A pulse shaper has a periodically reversible capacitor for pulse shaping. In performing testing of electronic components, the test specimens must be driven with different or, respectively, variable pulses. To this end, the pulse shaper has two mutually symmetrical circuits serving for the periodic charging and discharging of the capacitor, the circuits respectively containing binarilly switched adjustable resistors for setting the rise time and fall time of the pulse edges of the pulses to be formed, as well as containing a current source and a voltage source for the proportional change of the edge steepness with respect to the change of the shift of the pulses. In addition, voltage limitation is provided to generate the desired amplitude shift with respect to the baseline voltage with structure assigned to each circuit, the bias voltage sources of such structure being variable as a function of the shift to be set.

Abstract: A test facility comprises a transmitter and a receiver for an automatic test system for function testing of integrated circuits of different technologies, whereby the input and output of the test specimen are connected to the same test pin. In order to test circuits of different technological format, it is necessary to pre-program the output of the test facility to the respective characteristic level of the different circuit families. To this end, a transmitter contains a constant current source keyed by the inverted input signal with a TTL level related to zero volts, the constant current source being connected at its output to the input of an output stage provided with a dynamically variable constant current load.

Abstract: A transistor push-pull output stage, particularly for pulse shapers having inverse feedback from the output to the input, as well as a high-resistance input and a low-resistance output is disclosed. In testing components of data technology, short circuits in the component should not lead to the destruction of the output stage of the testing apparatus. To this end, the invention provides that a field effect transistor is employed in each push-pull stage as the input transistor, the field effect transistor respectively driving the parallel connection of a plurality of output transistors by way of an emitter follower stage. The bases of the output transistors are driven by way of a constant current source which is switched off given overvoltage of the output. The transistors and the push-pull stages are complementary to one another. In addition, a structure is provided for the power supply which is driven as a function of the voltage shift and of the pulse basic voltage of the signal.