LMX2336U Datasheet | National Semiconductor

Description The LMX2335U and LMX2336U are monolithic, integrated dual frequency synthesizers, including two high frequency prescalers, and are designed for applications requiring two RF phase-lock loops. The LMX2335U/36U 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. The LMX2335U/36U bined with a high quality reference oscillator, two loop filters, and two external voltage controlled oscillators generates very stable low noise RF local oscillator signals. Serial data is transferred into the LMX2335U/36U via a three wire interface (Data, Enable, Clock). Supply voltage can range from 2.7V to 5.5V. The LMX2335U/36U feature very low current consumption; LMX2335U - 3.0 m A at 3V, LMX2336U - 3.5 m A at 3V. The LMX2335U is available in a TSSOP 16-pin and CSP 16-pin surface mount plastic packages. The LMX2336U is available in a TSSOP 20-pin and CSP 24-pin surface mount plastic package. Features n Ultra low current consumption n 2.7V to 5.5V operation n Selectable synchronous and asynchronous 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 n Upgrade and patible to LMX2335L/36L n LMX2335U available in 16 - Lead TSSOP and 16 - Pin CSP n LMX2336U available in 20 - Lead TSSOP and 24 - Pin CSP Applications n Cellular telephone systems (AMPS, ETACS, RCR-27) n Cordless telephone systems (DECT, ISM , PHS, CT-1+) n Personal munication Systems (DCS-1800, PCN-1900) n Dual Mode PCS phones n Cable TV Tuners (CATV) n Other wireless munication systems Functional Block Diagram TRI-STATE® is a registered trademark of National Semiconductor Corporation. Fastlock™, MICROWIRE™ and PLLatinum™ are trademarks of National Semiconductor Corporation. © 2001 National Semiconductor Corporation DS101367 DS101367-1 .national....