MC74HC4046ADG

Clock Generators, PLLs, Frequency Synthesizers Overview

The MC74HC4046ADG is a high-performance silicon-gate CMOS phase-locked loop (PLL) manufactured by onsemi. It integrates three distinct phase comparators, a linear voltage-controlled oscillator (VCO), and a unity gain operational amplifier for demodulation output. The device operates within a supply voltage range of 3.0 V to 6.0 V and supports an operating temperature range from -55°C to +125°C. Key electrical characteristics include a maximum quiescent current of 80 μA with the VCO disabled and input leakage currents limited to 1.0 μA. The component features diode protection on all inputs and provides an output drive capability equivalent to 10 LSTTL loads.

Clock Generators, PLLs, Frequency Synthesizers Feature Summary

• Integrates three phase comparators: XOR gate (PC1), edge-sensitive digital network (PC2), and RS flip-flop (PC3).
• Includes a linear VCO with frequency determined by external R1, R2, and C1 components.
• Features a unity gain op-amp buffer at DEMOUT to access VCOIN voltage without loading the loop filter.
• Provides an INH pin to disable the VCO and op-amps for minimized standby power consumption.

Clock Generators, PLLs, Frequency Synthesizers Applications

• FM and FSK modulation and demodulation circuits.
• Frequency synthesis and multiplication systems.
• Tone decoding and data synchronization conditioning.
• Voltage-to-frequency conversion and motor speed control.

Clock Generators, PLLs, Frequency Synthesizers Procurement Notes

Verify the ordering suffix 'G' confirms the package is lead-free as specified in the manufacturer's documentation. Confirm the SOIC-16 package dimensions match the CASE 751B specification. Check for any product change notices or end-of-life status updates from onsemi prior to procurement, as availability may vary.

Clock Generators, PLLs, Frequency Synthesizers Selection Notes

Select this component when a single-chip PLL solution with multiple comparator options is required for CMOS logic compatibility. Ensure the application voltage remains between 3.0 V and 6.0 V. Consider the specific phase comparator requirements: PC1 for 90-degree phase shift, PC2 for zero-phase shift, or PC3 for edge-triggered operation. Verify that the external R1, R2, and C1 values fall within the recommended ranges for the desired VCO center frequency and lock range.

Clock Generators, PLLs, Frequency Synthesizers Part Context

The MC74HC4046ADG belongs to the 74HC4046A family of high-speed CMOS logic devices. It is functionally similar to the older MC14046 metal-gate CMOS device but offers improved operating speeds comparable to LSTTL. The 'ADG' designation specifically indicates the SOIC-16 surface-mount package variant that is lead-free compliant.

Clock Generators, PLLs, Frequency Synthesizers Replacement Considerations

Direct functional substitutes include other manufacturers' 74HC4046 variants such as CD74HC4046AM from Texas Instruments. When replacing, ensure the alternative part supports the same 3.0 V to 6.0 V operating voltage and maintains compatibility with the SOIC-16 footprint if board space is constrained.