Integrated Circuit Form Research Articles

A silicon diode analogue multiplier

The logarithmic nature of the voltage-current characteristics of silicon junction diodes is exploited to design an analogue multiplier. Four silicon junction diodes are used in conjunction with a differential operational amplifier in the multiplier circuit. The principle of operation, design considerations and techniques to compensate for temperature effects and unequal diode parameters are discussed. Methods of performing division and generation of special types of functions are outlined. Measurements on an experimental single quadrant multiplier show that an accuracy of multiplication of the order of 1% can be achieved. Long term temperature drift at the output is measured to be 2% per 10 degC change in ambient temperature. The bandwidth of the multiplier is directly dependent on the operational amplifier employed. With a Donner (Model 3400) amplifier, the bandwidth is measured to be about 200 Hz. An attractive feature of the circuit is that it lends itself for miniaturization with the advent of differential operational amplifiers in the integrated circuit form.

Oscillators, modulators, and mixers suitable for integrated circuit realization

It is shown how the variable grounded gyrators now becoming available in integrated-circuit form can be used in conjunction with transistors and capacitors to obtain oscillators, modulators, and mixers.

Laser micromachining aids large-scale integration

A laser machining technique recently developed at Standard Telecommunication Laboratories should enable a wide variety of circuit functions to be realised very simply in large-scale integrated-circuit form.

Direct-coupled gyrator suitable for integrated circuits and time variation

A direct-coupled gyrator circuit which can be easily realised in integrated-circuit form is described. Since the gyrator action extends to d.c., it is practicable to realise d.c. transformers by cascading two such gyrators.

"UNIVER"—A fast, versatile multilogic digital amplifier for micrologic circuits

The nature of integrated circuit fabrication limits the number of circuit modules in a system due to the high developmental cost involved. This paper describes a unique approach to designing an ultra-high speed multiple-function logic amplifier in integrated circuit form. Using the scheme of a pair of tunnel-diode coupled emitter followers driven by an emitter-coupled amplifier, it is shown that the circuit, designated UNIVER, has a capability of both storage (flip-flop) and wave-shaping functions, and can drive low impedance (35 ohms) transmission lines with a high (8) logic gain under 1 nsec total stage delay, while suppressing the oscillatory ringing commonly occurring in an emitter follower. A large number of the UNIVER circuits were built in integrated circuit form and then evaluated as multiple functional modules in a 100-Mc digital system. The logical performance and switching characteristics of the circuits were ascertained. Test results collected over a twelve-month period are discussed as well as the extended applications of the UNIVER circuit scheme.