Microwave wideband synthesizer integrates VCO

The ADF5355 from Analog Devices allows implementation of fractional-N or integer-N phase-locked loop (PLL) frequency synthesizers when used with an external loop filter and an external reference frequency. Now available from Digi-Key, the device's wideband microwave VCO design permits frequency operation from 6.8GHz to 13.6GHz at one radio frequency (RF) output. A series of frequency dividers at another frequency output permits operation from 54MHz to 6800MHz. The ADF5355 has an integrated VCO with a fundamental output frequency ranging from 3400MHz to 6800MHz. In addition, the VCO frequency is connected to divide by 1, 2, 4, 8, 16, 32, or 64 circuits that allow the user to generate RF output frequencies as low as 54MHz. For applications that require isolation, the RF output stage can be muted. The mute function is both pin and software controllable. Control of all on-chip registers is through a simple 3-wire interface. The ADF5355 operates with analog and digital power supplies ranging from 3.15V to 3.45V, with charge pump and VCO supplies from 4.75V to 5.25V. The ADF5355 also contains hardware and software power-down modes.