Microwave Wideband Synthesizer with Integrated VCO

The ADF4372 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. The wideband microwave voltage controlled oscillator (VCO) design allows frequencies from 62.5 MHz to 16 GHz to be generated.

The ADF4372 has an integrated VCO with a fundamental output frequency ranging from 4000 MHz to 8000 MHz. In addition, the VCO frequency is connected to a divide by 1, 2, 4, 8, 16, 32, or 64 circuit that allows the user to generate radio frequency (RF) output frequencies as low as 62.5 MHz at RF8x. A frequency multiplier at RF16x generates from 8 GHz to 16 GHz. RFAUX8x duplicates the frequency range of RF8x or permits direct access to the VCO output. To suppress the unwanted products of frequency multiplication, a harmonic filter exists between the multiplier and the output stage of RF16x.

Control of all on-chip registers is through a 3-wire interface. The ADF4372 operates with analog and digital power supplies ranging from 3.15 V to 3.45 V, and 5 V for the VCO power supply. The ADF4372 also contains hardware and software power-down modes.

APPLICATIONS

* Wireless infrastructure (multicarrier global system for mobile communication (MC-GSM), 5 G)

* Test equipment and instrumentation

* Clock generation

* Aerospace and defense

* RF output frequency range: 62.5 MHz to 16,000 MHz

* Fractional-N synthesizer and integer-N synthesizer

* High resolution 39-bit fractional modulus

* Typical spurious fPFD: −90 dBc

* Integrated rms jitter: 38 fs (1 kHz to 100 MHz)

* Normalized phase noise floor: −234 dBc/Hz

* fPFD operation to 250 MHz

* Reference input frequency operation to 600 MHz

* Programmable divide by 1, 2, 4, 8, 16, 32, or 64 output