4046 Phase-Locked Loop (PLL) with VCO

A CD4046 CMOS integrated circuit providing a phase-locked loop with voltage controlled oscillator. A complete PLL, used for frequency synthesis, clock recovery, tone decoding and frequency multiplication. One of the more capable chips in the 4000 family. Being 4000-series CMOS it runs on anything from 3 to 18 volts, which makes it far more flexible than 5V-only TTL logic and lets it work directly in battery and higher voltage circuits. It also draws almost no current when idle. The trade-off is speed: CMOS of this family is slower than 74HC logic, so it suits control, timing and teaching applications rather than fast data paths. Unused inputs must be tied to a supply rail, never left floating. Wide 3-18V supply range, unlike 5V-only TTL; Extremely low quiescent current suits battery circuits; High noise immunity from the wide logic swing; Standard 16-pin DIP fits breadboards and sockets