The SP5668 is a single chip frequency synthesiser designed for tuning systems up to 2.7GHz.

The RF preamplifer contains a divide by two prescaler which can be disabled for applications up to 2GHz so enabling a step size equal to the comparison frequency up to 2GHz and twice the comparison frequency up to 2.7GHz.

Comparison frequencies are obtained either from a crystal controlled on–chip oscillator or from an external source.

The device contains three switching ports, P0 – P2, together with an ’in–lock’ flag output. Various test modes including varactor disable and charge pump disable are also included.

FEATURES

■ Complete 2.7GHz single chip system

■ Optimised for low phase noise

■ Selectable divide by two prescaler

■ Selectable reference division ratio

■ Charge pump disable

■ Varactor line disable

■ ‘In–lock’ flag

■ Two selectable charge pump currents

■ Three switching ports

■ Reference frequency output

■ ESD protection (Normal ESD handling procedures should be observed)

APPLICATIONS

■ SAT, TV, VCR and Cable tuning systems

■ Communications systems