Figure 1 shows a block diagram of a PLL-based ... October 2014. “Circuit Note CN-0228: Single-Supply Power a 28 V, High Voltage Phase-Locked Loop (PLL) Synthesizer.” Analog Devices, June ...

I had never heard of the 74HCT9046 phase-locked loop before a fortnight ago ... It is all down to the voltage-based output – a tri-state output that was either: open-circuit connected to Vcc connected ...