General Description
●The LMX2315/2320/2325’s are high performance frequency synthesizers with integrated prescalers designed for RF operation up to 2.5 GHz. They are fabricated using National’s ABiC IV BiCMOS process.
●A 64/65 or a 128/129 divide ratio can be selected for the LMX2315 and LMX2320 RF synthesizer at input frequencies of up to 1.2 GHz and 2.0 GHz, while 32/33 and 64/65 divide ratios are available in the 2.5 GHz LMX2325. Using a proprietary digital phase locked loop technique, the LMX2315/2320/2325’s linear phase detector characteristics can generate very stable, low noise signals for controlling a local oscillator.
●Features
●■ RF operation up to 2.5 GHz
●■ 2.7V to 5.5V operation
●■ Low current consumption
●■ Dual modulus prescaler:
● LMX2325 32/33 or 64/65
● LMX2320/LMX2315 64/65 or 128/129
●■ Internal balanced, low leakage charge pump
●■ Power down feature for sleep mode:
● ICC e 30 mA (typ) at VCC e 3V
●■ Small-outline, plastic, surface mount TSSOP, 0.173" wide
●Applications
●■ Cellular telephone systems
● (GSM, IS-54, IS-95, (RCR-27)
●■ Portable wireless communications (DECT, PHS)
●■ CATV
●■ Other wireless communication systems
