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SP8853A/B
1·3GHz Professional Synthesiser
Supersedes March 1997 version, DS2352 - 3.0 DS2352 - 4.0 March 1998
The SP8853 is a low power single chip synthesiser intended for professional radio applications, containing all the elements (apart from the loop amplifier) required to build a PLL frequency synthesis loop The device is serially programmable by a three-wire data highway and contains three independent buffers to store one reference divider word and two local oscillator divider words. A digital phase detector with two charge pumps, programmable in phase and gain, are provided to improve lock-up performance. The preset operation of the charge pumps can be overwritten or the comparison frequencies switched to output ports under control of the divider word.