LMX2372 Datasheet | National Semiconductor

Features n n n n n 2.7V- 5.5V operation Ultra low current consumption Low phase detector noise floor Low voltage MICROWIRE™ interface (1.8V up to VCC) Low prescaler values 32/33 @ f IN ≤ 2.5 GHz 16/17 @ f IN ≤ 1.2 GHz 8/9 @ f IN ≤ 550 MHz Selectable charge pump current levels Selectable Fast Lock™ mode Enhanced ESD protection Small 24 pad chip scale package (3.5 x 4.5 x 1.0 mm) General Description The LMX237X family of monolithic, integrated dual frequency synthesizers, including prescalers, is designed to be used as a first and second local oscillator for dual mode or dual conversion transceivers. It is fabricated using National’s 0.5u ABi CV silicon Bi CMOS process. The LMX237X contains two dual modulus prescalers. A 32/33 or a 16/17 prescaler can be selected for the 2.5 GHz and 2.0 GHz RF synthesizers with the 16/17 prescaler rated for input frequencies below 1.2 GHz. A 16/17 or an 8/9 prescaler can be selected for the 1.2 GHz RF synthesizers with the 8/9 prescaler rated for input frequencies below 550 MHz. Using a digital phase locked loop technique, the LMX237X can generate very stable, low noise control signals for UHF and VHF voltage controlled oscillators (VCO’s). Serial data is transferred into the LMX237X via a 1.8V three wire interface (Data, Enable, Clock) patible with low voltage baseband processors. Supply voltage can range from 2.7V to 5.5V. The LMX237X family features very low current consumption typically: LMX2370 - 6.0 m A @ 3V, LMX2371 - 5.0 m A @ 3V, LMX2372 - 4.0 m A @ 3V. n n n n Applications n n n n Portable wireless munications (PCS/PCN, cordless) Dual mode cellular telephone systems Spread spectrum munication systems (CDMA) Cable TV tuners (CATV) Functional Block Diagram DS101026-1 Fast Lock™, PLLatinum™ and MICROWIRE™ are trademarks of National Semiconductor Corporation. TRI-STATE ® is a registered trademark of National Semiconductor Corporation. © 1999 National Semiconductor Corporation DS101026 .national. Connection Diagrams TSSOP 20-Pin...