The SFS1900A-LF from Z-COMM is a Frequency Synthesizer with Frequency 1.9 GHz, Reference Frequency 10 MHz, Output Power 0 to 6 dBm, Spurious -70 dBc, Supply Voltage 3.3 V. Tags: Surface Mount, PLL Frequency Synthesizer. More details for SFS1900A-LF can be seen below.