LMX2337

LMX2335/LMX2336/LMX2337 PLLatinum Dual Frequency Synthesizer for RF Personal Communications September 1996 LMX2335/LMX2336/LMX2337 PLLatinum™ Dual Frequency Synthesizer for RF Personal Communications LMX2335 LMX2336 LMX2337 1.1 GHz/1.1 GHz 2.0 GHz/1.1 GHz 550 MHz/550 MHz both a JEDEC SO and TSSOP 16-pin surface mount plastic package. The LMX2336 is available in a TSSOP 20-pin surface mount plastic package. Features n 2.7V to 5.5V operation n Low current consumption n Selectable powerdown mode: ICC = 1 µA (typ) n Dual modulus prescaler: 64/65 or 128/129 n Selectable charge pump TRI-STATE ® mode n Selectable charge pump current levels n Selectable FastLock™ mode General Description The LMX2335, LMX2336 and LMX2337 are monolithic, integrated dual frequency synthesizers, including two high frequency prescalers, and are designed for applications requiring two RF phase-lock loops. They are fabricated using National’s ABiC IV silicon BiCMOS process. The LMX2335/36/37 contains two dual modulus prescalers. A 64/65 or a 128/129 prescaler can be selected for each RF synthesizer. A second reference divider chain is included in the IC for improved system noise. LMX2335/36/37, which employ a digital phase locked loop technique, combined with a high quality reference oscillator and loop filters, provide the tuning voltages for voltage controlled oscillators to generate very stable low noise RF local oscillator signals. Serial data is transferred into the LMX2335/36/37 via a three wire i...