CD4046 PLL Frequency Multiplier

Use a CMOS phase-locked loop and one feedback divider to multiply a slow reference clock by an integer.

Difficulty: Through-hole. Estimated build time: about 45 minutes. Estimated parts cost: about US$3.00. 4-part bill of materials with live supplier pricing. A textbook phase-locked loop built from the TI CD4046, a single CMOS chip that contains the three pieces you need: a phase comparator, a low-pass loop filter (you add the resistors and capacitor externally), and a voltage-controlled…