The ADF5612 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 source. The wideband
microwave voltage controlled oscillator (VCO) design permits
frequency operation from 7300MHz to 8500MHz at a single RF
output. A series of frequency dividers with a differential frequency
output allows operation from 57MHz to 8500MHz. Analog and
digital power supplies for the PLL circuitry range from 3.15V to
3.45V, and the VCO supplies are between 4.75V and 5.25V.
The ADF5612 has an integrated VCO with a fundamental frequency
of 3650MHz to 7300MHz. These frequencies are internally doubled
and routed to the RFOUT 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 57MHz. A simple 3-wire or 4-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. Likewise, the output power for both the single-ended output
and the differential output are programmable.
The integrated phase detector and Δ-Σ modulator, capable of operating
at up to 100MHz, permit wide loop bandwidths and fast
frequency tuning with a typical spurious level of −105dBc.
With a VCO open-loop phase noise at 100kHz offset of −115dBc/Hz
at 7.3GHz RFOUT. The ADF5612 is equipped to minimize blocker
effects and to improve receiver sensitivity and transmitter spectral
purity. The low phase noise floor eliminates any contribution to
modulator and mixer noise floor in transmitter applications.
APPLICATIONS
- Military and defense
- Test equipment
- Clock generation
- Wireless infrastructure
- Satellite and very small aperture terminals (VSATs)
- Microwave radios
