Frequency synthesizer system with integrated VCOs

LMX2502 and LMX2512 are highly integrated, high performance, low power frequency synthesizer systems optimized for Korean PCS and Korean Cellular CDMA (1xRTT, IS-95) mobile handsets. Using a proprietary digital phase locked loop technique, LMX2502 and LMX2512 generate very stable, low noise local oscillator signals for up and down conversion in wireless communications devices.

LMX2502 and LMX2512 include a voltage controlled oscillator (VCO), a loop filter, and a fractional-N RF PLL based on a delta sigma modulator. In concert these blocks form a closed loop RF synthesizer system. LMX2502 supports the Korean PCS band and LMX2512 supports the Korean Cellular band.

LMX2502 and LMX2512 include an Integer-N IF PLL also. For more flexible loop filter designs, the IF PLL includes a 4-level programmable charge pump. Together with an external VCO and loop filter, LMX2502 and LMX2512 make a complete closed loop IF synthesizer system.

Serial data is transferred to the device via a three-wire MICROWIRE interface (DATA, LE, CLK).

Operating supply voltage ranges from 2.7 V to 3.3 V. LMX2502 and LMX2512 feature low current consumption: 17 mA at 2.8 V.

LMX2502 and LMX2512 are available in a 28-pin WQFN package.