LMX2372

LMX2370/LMX2371/LMX2372 PLLatinum Dual Frequency Synthesizer for RF Personal Communications PRELIMINARY March 1999 LMX2370/LMX2371/LMX2372 PLLatinum™ Dual Frequency Synthesizer for RF Personal Communications LMX2370 LMX2371 LMX2372 2.5 GHz/1.2 GHz 2.0 GHz/1.2 GHz 1.2 GHz/1.2 GHz The LMX237X are available in a 24-pad chip scale (CSP) or a 20-pin TSSOP surface mount plastic package. 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 @ fIN ≤ 2.5 GHz 16/17 @ fIN ≤ 1.2 GHz 8/9 @ fIN ≤ 550 MHz Selectable charge pump current levels Selectable FastLock™ 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 ABiCV silicon BiCMOS 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 ...