SP5848

Preliminary Information SP5848 SP5848 2.2/1.3GHz 3-Wire Bus Dual Low Phase Noise PLL Preliminary Information DS5076 Issue 1.6 October 1999 Features G Ordering Information SP5848/KG/QP1S SP5848/KG/QP1T G G G Dual independent PLL frequency synthesisers in a single package, optimised for double conversion cable tuners, offering improved application 2.2GHz up-synthesiser optimised for low phase noise up to comparison frequencies of 4MHz 1.3GHz down-synthesiser optimised for low phase noise AND small step size Common reference oscillator and divider with independently selectable ratios for each synthesiser 10:1 programmable charge pump current ratio in up synthesiser 3-Wire bus programmable, each synthesiser indepently addressable Low power consumption, typ 100mW at 5V ESD protection, (Normal ESD handling procedures should be observed) Description The SP5848 is a dual PLL frequency synthesizer controlled by a 3-wire bus optimised for application in double conversion tuners. Each synthesiser loop within the SP5848 is independently addressable and contains an RF programmable divider, phase/frequency detector and charge pump/loop amplifier section; a common reference frequency oscillator and divider chain is provided, whose ratios for each loop are independently programmable. Both synthesisers are optimised for low phase noise performance and in addition synthesiser 2 is capable of operation with a low comparison frequency. G G G G Applications G TV, VCR, and cable tuning s...