LMX2485E - National Semiconductor

LMX2485E High Performance Delta-Sigma Low Power Dual PLLatinum Frequency Synthesizers

The LMX2485 is a low power, high performance delta-sigma fractional-N PLL with an auxiliary integer-N PLL. The device is fabricated using National Semiconductor’s advanced process. With delta-sigma architecture, fractional spurs at lower offset frequencies are pushed to higher frequencies outside the loop bandwidth. The ability to push close in spur and phas.

Features

Quadruple Modulus Prescalers for Lower Divide Ratios n RF PLL: 8/9/12/13 or 16/17/20/21 n IF PLL: 8/9 or 16/17 Advanced Delta Sigma Fractional Compensation n 12 bit or 22 bit selectable fractional modulus n Up to 4th order programmable delta-sigma modulator Features for Improved Lock Times and Programming n Fastlock / Cycle slip reduction n Integrated time-out counter n Single word write to change frequencies with Fastlock Wide Operating Range n LMX2485 RF PLL: 500 MHz to 3.0 GHz n LMX2485E RF PLL: 50 MHz to 3.0 GHz Useful Features n Digital lock detect output n Hardware and software power-dow.