LMX2542 PLLatinum Cellular and GPS Frequency Synthesizer System with Integrated VCOs
May 2004
LMX2542 PLLatinumTM Cell...
LMX2542 PLLatinum Cellular and GPS Frequency Synthesizer System with Integrated VCOs
May 2004
LMX2542 PLLatinumTM Cellular and GPS Frequency Synthesizer System with Integrated VCO
General Description
LMX2542 is a highly integrated, high performance, low power frequency synthesizer system optimized for CellularCDMA 1xRTT and IS-95 mobile handsets and data systems with GPS capabilities. Using a proprietary digital phase locked loop technique, LMX2542 provides very stable, low noise local oscillator (LO) signals for up and down conversion in wireless communications devices. LMX2542 includes a
Voltage Controlled Oscillator (VCO) for both the Cellular-CDMA and GPS frequency bands, a loop filter, and a Fractional-N RF PLL based on a Delta Sigma (∆Σ) modulator. In concert, these blocks form a closed loop RF synthesizer system. The RF synthesizer system operates from 2087.73 MHz to 2155.14 MHz. LMX2542 includes 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, LMX2542 makes a complete closed loop IF synthesizer system. The default IF frequency is 367.20 MHz. Serial data is transferred to the device via a three-wire MICROWIRETM interface (DATA, LE, CLK). Operating supply
voltage ranges from 2.7V to 3.3V. LMX2542 features low current consumption: 22 mA at 2.8V. LMX2542 is available in a 28-Pin Leadless Leadframe Package (LLP).
Features
n Small Size 5.0 mm x 5.0 mm x ...