Phase-locked loop with on-chip VCO — 38 MHz ceiling
The Texas Instruments CD74HCT4046AM is a single-circuit phase-locked loop (PLL) with an integrated voltage-controlled oscillator (VCO), built in the 74HCT CMOS logic family. It accepts CMOS-level inputs and delivers CMOS-level outputs, running from a 4.5V to 5.5V supply rail — a strict 5V part, not a wide-voltage CMOS PLL. The VCO can lock up to 38 MHz, which covers the common clock-recovery and frequency-synthesis range for 8-bit/16-bit microcontroller systems, serial data links, and tone decoding.
The operating temperature span of -55°C to 125°C covers the military temperature range.
The CD74HCT4046AM provides a 1:4 ratio from its single-phase input to four outputs. That means the VCO output and the phase-comparator outputs are available simultaneously, which simplifies the external loop-filter design — you can monitor the VCO signal while the feedback path runs through the phase comparator. The part has no built-in divider or multiplier (Divider/Multiplier = No/No), so any frequency scaling must be done externally. For a clean lock, budget for a passive RC loop filter between the phase-comparator output and the VCO input pin.
No last-time-buy math needed for a new design — this part will be around for the foreseeable production run.
16-SOIC narrow body — standard footprint
Housed in a 16-pin SOIC package with 3.90 mm body width (narrow SOIC-16), the CD74HCT4046AM uses a common, well-understood land pattern. No thermal pad, no exposed paddle — just a straightforward surface-mount package that reflows on a standard profile.