MM74HC4046N

Overview

The MM74HC4046N is a low-power CMOS Phase Lock Loop (PLL) manufactured by onsemi, housed in a 16-lead Plastic Dual-In-Line (PDIP) package. It integrates a linear Voltage Controlled Oscillator (VCO), a source follower, and three distinct phase comparators: an Exclusive OR gate (PC I), an edge-sensitive digital sequential network (PC II), and an SR flip-flop (PC III). The device operates within a supply voltage range of 2 V to 6 V and supports frequencies up to 12 MHz at 4.5 V. It features high linearity, fast comparator response times, and an inhibit pin for low-power shutdown.

Feature Summary

• Integrates three phase comparators: XOR (PC I), Edge-Sensitive (PC II), and SR Flip-Flop (PC III)
• Low dynamic power consumption with high-frequency operation
• Maximum VCO operating frequency of 12 MHz at VCC = 4.5 V
• Fast comparator response times ranging from 25 ns to 30 ns

Applications

• Frequency synthesis circuits
• Clock recovery systems
• FM demodulation

Procurement Notes

Verify the specific ordering suffix 'N' corresponds to the 16-lead PDIP package (JEDEC MS-001, 0.300" wide) as listed in the datasheet. Confirm that the component is sourced from onsemi or its authorized predecessors, such as Fairchild Semiconductor, given the historical branding. Ensure the revision date aligns with the October 2003 update referenced in the documentation.

Selection Notes

Select this component when a single-chip PLL solution with multiple comparator options is required. PC II is suitable for applications demanding zero phase shift lock and equal capture/lock ranges, while PC I offers better noise rejection. Ensure external components R1, R2, and C1 are selected to define the desired center frequency and lock range according to the provided performance curves.

Part Context

This device belongs to the 74HC series of high-speed CMOS logic devices. It is functionally similar to the CD4046 but utilizes advanced silicon-gate technology for higher speed and lower power. The MM74HC4046 replaces the Zener diode found in older metal-gate CMOS versions with a third phase comparator, expanding its functional versatility.

Replacement Considerations

Compatible replacements include other variants of the 74HC4046 family, such as MM74HC4046M (SOIC) or MM74HC4046MTC (TSSOP), provided the package footprint is adapted. Cross-manufacturer equivalents like the CD74HC4046A may be considered if electrical specifications match the design requirements.