VERSATILE LSI FREQUENCY SYNTHESISER SYSTEM.

Two LOCMOS LSI integrated circuits can be used to produce a flexible, low-cost, frequency synthesiser. The ICs contain all the critical circuits, both analogue and digital, to enable a programmable phase-locked-loop frequency synthesiser to be built easily and compactly. This article describes the ICs, their connection as a frequency synthesiser system, and the method used to overcome noise problems usually associated with phase-locked-loop frequency synthesisers. The novel technique for simplifying high speed frequency division (multiple feedback division) is also described.