Phase-Frequency Detectors

Analog Devices has introduced two HBT digital Phase-Frequency Detectors (PFD) intended for use in low-noise, Phase-Lock Loop (PLL) applications for inputs from 10 to 1300 MHz. Synthesizer designers can choose either the HMC439QS16G single-function PFD or the HMC440QS16G PFD with an integrated DC to 2800 MHz 5-bit counter. The counter offers continuous division from 2 to 32. Both products are housed in plastic SMT, 16-lead QSOP packages that have an exposed base for excellent RF and thermal performance.

Combining a high operating frequency of 10 to 1300 MHz, along with an ultra-low SSB phase noise floor of -153dBc/Hz at 10 kHz offset, both the HMC439QS16G and the HMC440QS16G make synthesizers with wide loop bandwidth and low N possible. The result is fast switching and very-low synthesizer phase noise. When used in conjunction with a differential loop amplifier, both PFDs generate an output voltage of 2 Vpk-pk typical that can be used to phase lock a VCO to a reference oscillator.