MC74HC4046AFELG

Clock Generators, PLLs, Frequency Synthesizers Overview

The MC74HC4046AFELG is a high-performance silicon-gate CMOS phase-locked loop (PLL) manufactured by onsemi. It integrates three phase comparators, a voltage-controlled oscillator (VCO), and a unity gain operational amplifier (DEMOUT). 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 output drive capability for 10 LSTTL loads. The part is housed in a 16-pin SOEIAJ package.

Clock Generators, PLLs, Frequency Synthesizers Feature Summary

• Integrates three distinct phase comparators: XOR gate (PC1), edge-sensitive digital memory network (PC2), and RS flip-flop (PC3).
• Features a linear voltage-controlled oscillator (VCO) with a center frequency up to 13 MHz at 6.0 V supply.
• Includes a unity gain op-amp buffer (DEMOUT) for accessing the VCO input voltage without loading the loop filter.
• Provides an inhibit input to disable the VCO and op-amps, minimizing 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 that the ordering suffix 'G' corresponds to the Pb-Free package variant as specified in the manufacturer's documentation. Confirm the package type is SOEIAJ-16 and check for RoHS compliance status. Ensure the component meets the required industrial temperature grade (-55°C to +125°C) for the intended application environment.

Clock Generators, PLLs, Frequency Synthesizers Selection Notes

Select this component when a single-chip PLL solution with multiple comparator options is required. Choose Phase Comparator 1 for applications requiring harmonic rejection, or Phase Comparator 2 for zero-phase-lock detection. Ensure external components R1, R2, and C1 are selected to keep the VCO frequency within the 13 MHz limit at 6.0 V. Verify that input signals are compatible with standard CMOS levels or utilize AC coupling for small signals.

Clock Generators, PLLs, Frequency Synthesizers Part Context

This device belongs to the 74HC series 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 MC74HC4046A family includes various package options such as PDIP, SOIC, TSSOP, and SOEIAJ, with the AFELG designation specifically indicating the reel-packaged, lead-free SOEIAJ-16 version.

Clock Generators, PLLs, Frequency Synthesizers Replacement Considerations

Direct substitutes include other manufacturers' 74HC4046 variants in compatible packages. Verify pinout compatibility, particularly for the DEMOUT and INH pins, when replacing with non-onsemi parts. Ensure the replacement device supports the same 3.0 V to 6.0 V operating voltage range and industrial temperature specifications.