Fractional-N PLL - TSMC 28 CLN28HPC

The programmable Fractional-N divider allows the PLL to lock to an incoming clock source and produce an output clock with a non-integer multiplication factor. The generated clock can be locked to the input source yet adjusted to a fine-degree of precision, and may be adjusted on-the-fly to maintain a relatively drifting local clock need. The updatable programmable fractional feedback divider is provided for this purpose. “On the fly” capability means the frequency transition and re-obtaining lock process for small frequency adjustment is glitch free and contains limited frequency over/undershoot.