LMX2353 Datasheet | National Semiconductor

Description The LMX2353 is a monolithic integrated fractional N frequency synthesizer, designed to be used in a local oscillator subsystem for a radio transceiver. It is fabricated using National’s 0.5µ ABi C V silicon Bi CMOS process. The LMX2353 contains dual modulus prescalers along with modulo 15 or 16 fractional pensation circuitry in the N divider. A 16/17 or 32/33 prescale ratio can be selected for the LMX2353. Using a fractional N phase locked loop technique, the LMX2353 can generate very stable low noise control signals for UHF and VHF voltage controlled oscillators (VCO’s). The LMX2353 has a highly flexible 16 level programmable charge pump supplies output current magnitudes from 100 µA to 1.6 m A. Serial data is transferred into the LMX2353 via a three wire interface (Data, LE, Clock). Supply voltage can range from 2.7V to 5.5V. The LMX2353 features very low current consumption; typically 4.5 m A at 3.0V. The LMX2353 is available in a 16-pin TSSOP or a 16-pad CSP surface mount plastic package. Features n 2.7V - 5.5V operation n Low Current Consumption ICC = 4.5 m A typ @ VCC = 3.0V n Programmable or Logical Power Down Mode ICC = 5 µA typ @ VCC = 3.0V n Modulo 15 or 16 fractional N divider Supports ratios of 1, 2, 3, 4, 5, 8, 15, or 16 n Programmable charge pump current levels 100 µA to 1.6 m A in 100 µA steps n Digital Filtered Lock Detect Applications n n n n Portable wireless munications (PCS/PCN, cordless) Zero blind slot TDMA systems Cellular and Cordless telephone systems Spread spectrum munication systems (CDMA) Functional Block Diagram DS101124-1 MICROWIRE™ and PLLatinum™ are trademarks of National Semiconductor Corporation. TRI-STATE ® is a registered trademark of National Semiconductor Corporation. © 1999 National Semiconductor Corporation DS101124 .national. Connection Diagrams DS101124-2 DS101124-3 TOP VIEW Order Number LMX2353TM or LMX2353TMX See NS Package Number MTC16 TOP VIEW Order Number LMX2353SLBX See NS Package Number...