LMX2371

The LMX2371 family of monolithic, integrated dual fre-quency synthesizers, including prescalers, is designed to beused as a first and second local oscillator for dual mode ordual conversion transceivers. It is fabricated using National's0.5u ABiCV silicon BiCMOS process. The LMX237X con-tains two dual modulus prescalers. A 32/33 or a 16/17prescaler can be selected for the 2.5 GHz and 2.0 GHz RFsynthesizers with the 16/17 prescaler rated for input frequen-cies below 1.2 GHz. A 16/17 or an 8/9 prescaler can be se-lected for the 1.2 GHz RF synthesizers with the 8/9 prescalerrated for input frequencies below 550 MHz. Using a digitalphase locked loop technique, the LMX2371 can generatevery stable, low noise control signals for UHF and VHF volt-age controlled oscillators (VCO's). Serial data is transferredinto the LMX237X via a 1.8V three wire interface (Data, En-able, Clock) compatible with low voltage baseband proces-sors. Supply voltage can range from 2.7V to 5.5V. TheLMX237X family features very low current consumption typi-cally: LMX2370 - 6.0 mA @ 3V, LMX2371 - 5.0 mA @ 3V,LMX2372 - 4.0 mA @ 3V.

The LMX2371 are available in a 24-pad chip scale (CSP) or a 20-pin TSSOP surface mount plastic package.