LMX2471 - National Semiconductor

LMX2471 3.6 GHz Delta-Sigma Fractional-N PLL

The LMX2471 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 BiCMOS process. With delta-sigma architecture, fractional spur compensation is achieved with noise shaping capability of the delta-sigma modulator and the inherent low pass filtering of th.

Features

a typical current consumption of 5.6 mA at 2.5 V. The LMX2471 is available in a 24 lead 3.5 X 4.5 X 0.6 mm package. Features n n n n Low in-band phase noise and low fractional spurs 12 bit or 22 bit selectable fractional modulus Up to 4th order programmable delta-sigma modulator Enhanced Anti-Cycle Slip Fastlock Circuitry Fastlock Cycle slip reduction Integrated timeout counters Digital lock detect output Prescalers allow wide range of N values RF PLL: 16/17/20/21 IF PLL: 8/9 or 16/17 Crystal Reference Frequency up to 110 MHz On-chip crystal reference frequency doubler. Phase Comparison Frequ.