Analog Devices' ADF5610 allows the implementation of fractional-N or integer-N phase-locked loop (PLL) frequency synthesizers when used with an external loop filter and an external reference source. The wideband microwave voltage-controlled oscillator (VCO) design permits frequency operation from 7300 MHz to 14600 MHz at a single radio frequency (RF) output. A series of frequency dividers with a differential frequency output allows operation from 57 MHz to 14600 MHz. Analog and digital power supplies for the PLL circuitry range from 3.1 V to 3.5 V and the VCO supplies are between 4.75 V and 5.25 V. The charge pump supply voltage can be extended up to 3.6 V for improved frequency band overlap and extended upper-frequency range.

The ADF5610 has an integrated VCO with a fundamental frequency of 3650 MHz to 7300 MHz. These frequencies are internally doubled and routed to the RF_OUT pin. An additional differential output allows the doubled VCO frequency to be divided by 1, 2, 4, 8, 16, 32, 64, or 128, allowing the user to generate RF output frequencies as low as 57 MHz. A simple 3-wire serial port interface (SPI) provides control of all on-chip registers. To conserve power, this divider block can be disabled when not needed through the SPI interface. Likewise, the output power for both the single-ended output and the differential output are programmable via the VCO register settings. The ADF5610 also contains various power-down modes for the VCO circuitry and PLL circuitry.