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What is the shortest locking time for PLL%2B VCO in the new release parts?

  • 2 components make up the Lock Time  VCO calibration time & PLL Loop Settling Time. For PLL loop settling time: lock time is usually around 5/(2*pi*loop filter BW). Larger loop BW will have faster settling times. There are trade-offs between performance and loop settling times.

    Lock time also depends on the loop bandwidth & loop filter. Auto Calibration time is about 1ms for the ADF4371 & ADF4372 PLL+VCO’s but you can use the bypass mode which would significantly reduce the calibration time. See Appnote AN-2005 on the ADI website that details how to reduce locking time for the ADF4371 & ADF4372 family but bypassing Auto Calibration. You can also use ADISimPLL models to simulate lock times for ADI parts.