200 MHz PLL clock generator in a 4x4 mm LFCSP
The ADF4001BCPZ is a phase-locked loop (PLL) clock generator from Analog Devices, built for RF synthesis applications where a clean, stable clock is needed from a lower-frequency reference. It accepts CMOS or TTL inputs and delivers a single clock output at frequencies up to 200 MHz. The 2:1 input-to-output ratio means the chip can select between two reference sources or divide the PLL output internally — useful when the system has a primary and a backup oscillator.
That saves a regulator and a couple of bypass caps on the BOM, but the trade-off is that the PLL charge-pump current and loop-filter component values need to be recalculated if the supply voltage changes between designs. Industrial temperature grade qualifies the part for outdoor and factory-floor environments where the ambient can hit 85 °C — common in telecom base stations, motor drives, and instrumentation.
Package and footprint notes for layout
The 20-WFQFN exposed-pad package has a 0.50 mm pitch. Differential input and output capability means the reference and the PLL output can be routed as differential pairs, which helps reject common-mode noise on long board traces or through connectors.