38 MHz PLL with VCO in a 16-TSSOP — what it is and where it fits
The Texas Instruments SN74LV4046APW is a phase-locked loop (PLL) with an integrated voltage-controlled oscillator (VCO), part of the 74LV low-voltage logic family. It accepts CMOS and TTL input levels and delivers CMOS and TTL output levels, running from a single 3 V to 5.5 V supply rail. The single PLL circuit provides a 1:3 input-to-output ratio, meaning the phase detector and VCO outputs are available on separate pins for flexible loop-filter design. With a maximum operating frequency of 38 MHz, this part is suited for frequency synthesis, clock recovery, FM demodulation, and tone decoding in industrial control, motor-drive feedback, and telecom infrastructure where the -40°C to 125°C temperature range covers harsh ambient conditions.
38 MHz ceiling — what it means for the loop
The 38 MHz maximum frequency sets the upper bound for the VCO and phase-detector operation. In practice, the loop bandwidth should be kept well below this — typically 1/10th to 1/20th of the VCO center frequency — to maintain stable lock and adequate phase margin. If your application requires locking above 38 MHz, this part will not close the loop; consider a higher-speed PLL family such as the 74HCT series (also 38 MHz but in a through-hole DIP) or a dedicated clock-multiplier IC. For designs that stay under 38 MHz, the 74LV4046APW offers a clean single-rail solution in a compact surface-mount footprint.
Supply range and temperature grade — BOM fit
The 3 V to 5.5 V supply range means this PLL can share a 3.3 V or 5 V rail with the rest of the logic, eliminating a dedicated regulator. The -40°C to 125°C operating temperature range qualifies it for industrial and automotive environments where the ambient can exceed 85°C — motor-drive cabinets, outdoor base stations, and under-hood electronics. The 16-TSSOP package (4.40 mm width) saves board area compared to the older SOIC-16 or DIP-16 footprints, which matters when routing dense mixed-signal boards.
Active lifecycle — no obsolescence pressure
The SN74LV4046APW carries an active product status and is ROHS3 compliant. Procurement can add this to the BOM without planning for a near-term replacement.