Abstract: For the testing of an integrated monolithic circuit (IC) the integrated monolithic circuit with a test bus which extends along a functional part of the circuit which is partitioned into macro circuits and which is coupled to the macro circuits, each macro circuit comprising a test interface circuit which is connected in series with test interface circuits of the other macro circuits; via the test interface circuits, the macro circuits can be coupled to the test bus. As a result, macro circuits can be separately tested and in the case of a hierarchic design of integrated circuits, utilizing previously designed marco circuits and test programs for previously designed macro circuits, test development times can be substantially reduced; this is an increasingly important aspect of increasingly complex circuits.

Abstract: Noise detector for selecting noise pulses from a non-limited FM radio broadcast signal modulated on a carrier, comprising an amplitude detection circuit and a signal comparison circuit. This signal comparison circuit produces a detection signal when its input signal exceeds a threshold level which varies with the average input level of the noise detection, for example, the average field strength. A noise selection being adapted to the human ear and based on the ratio between the noise pulse amplitude and the average input level is realized by means of a logarithmic level detection circuit. The logarithmic conversion therein renders a simple setting of the value of ratio possible, and provides a dynamic compression.

Abstract: A double-balanced RF mixer circuit comprising two differential amplifiers each of which comprises a pair of transistors the emitters of which are connected in common and the bases of which are cross-coupled to provide common first and second base terminals to which an oscillator signal is applied. A radio frequency signal to be mixed is applied to a voltage-current converter comprising a pair of transistors connected as a balanced common-base circuit, the collectors of such transistors being coupled to the common-emitter terminals of the differential amplifiers. Such a mixer circuit provides improved intermodulation and noise behaviour as compared with mixers in which the voltage-current converter is a conventional differential amplifier.