SKY73121

• Wideband frequency operation: 1805 to 1890 MHz
• Process-tolerant compensation for VCO
• 24-bit fractional-N synthesizer
• Ultra-fine frequency resolution of 0.001 ppm
• Flexible reference frequency selection
• Three-wire serial interface up to 20 MHz clock frequency
• Integrated PLL supply regulation for spur isolation
• MCM (38-pin, 9 x 12 mm) Pb-free free (MSL3, 260 °C per JEDEC J-STD-020) SMT package

1805-1890 MHz High Performance VCO/Synthesizer With Integrated Switch

Skyworks SKY73121 Voltage-Controlled Oscillator(VCO)/Synthesizer is a fully integrated, high performance signalsource for high dynamic range transceivers. The device providesultra-fine frequency resolution, fast switching speed, and lowphase noise performance for 2G, 2.5G, and 3G base stationtransceivers.

The SKY73121 VCO/Synthesizer is a key building block for highperformanceradio system designs that require low power and afine step size. Reference clock generators with an outputfrequency up to 52 MHz can be used with the SKY73121. Theinput clock frequency is divided down by programmable dividers(1 to 8) for the synthesizer. The phase detector can operate at amaximum speed of 26 MHz, which allows better phase noise dueto the lower division value.

The SKY73121 VCO/Synthesizer is provided in a compact, 38-pinMulti-Chip Module (MCM). The device package and pinout areshown in Figure 1. A functional block diagram is shown inFigure 2. Signal pin assignments and functional pin descriptionsare provided in Table 1.