SP8855E

SP8855E 2.8GHz Parallel Load Professional Synthesiser Advance Information Supersedes version in January 1996 Professional Products IC Hanbook, HB2480-3.0 DS4239 - 3.0 March 1999 The SP8855E is one of a family of parallel load synthesisers containing all the elements apart from the loop amplifier to fabricate a PLL synthesis loop. Other devices in the series are the SP8852E which is a fully programmable device requiring two 16 bit words to set the RF and reference counters, and the SP8854E which has hard wired reference counter programming and requires a single bit word to program the RF divider. The SP8855E replaces the existing SP8855D. The SP8855E is intended for applications where a fixed synthesiser frequency is required although it can also be used where frequency selection is set by switches. In general the device will be programmed by connecting the programming pins to either VCC or ground. Additional hard wired inputs can be used to control the Fpd and Fref outputs set the control direction of the loop and select the phase detector gain. Another input may be used to disable the phase detector output. The device is available in both plastic (HP) and ceramic (HC) J-leaded 44-lead chip carrier. Ambient temperature ranges available are shown in the ordering information. PIN 1 HC44 OPTIONAL PIN 1 REFERENCE FEATURES s 2.8GHz Operating Frequency (IG GRADE) s Single 5V Supply Operation s High Comparison Frequency 50MHz s High Gain Phase Detector 1mA/rad s Programmable Ph...