HC49US-FF3F18-4.000MHZ

Crystals Overview

The ILSI HC49US-FF3F18-4.000MHZ is a through-hole quartz crystal resonator operating at a nominal frequency of 4 MHz. It features a ±30 ppm frequency tolerance and stability, with an 18 pF load capacitance. The component utilizes the HC-49/US package, measuring 11.40 mm in length, 4.73 mm in width, and 4.50 mm in maximum height. Designed for base harmonic operation, it supports a temperature range of -40°C to +85°C and exhibits an equivalent series resistance (ESR) of 60 Ohms.

Crystals Feature Summary

• AT-cut quartz construction for stable oscillation
• RoHS compliant and lead-free processing compatible
• Standard HC-49/US through-hole mounting format

Crystals Applications

• T1/E1 system clock frequency generation
• Sonet/SDH network synchronization
• General-purpose microcontroller clock sources

Crystals Procurement Notes

Verify that the specific suffix FF3F18 corresponds to the required 18 pF load capacitance and 4 MHz frequency specification. Confirm that the HC-49/US package dimensions align with the target PCB footprint requirements. Ensure the ±30 ppm tolerance meets the system timing accuracy constraints before finalizing procurement orders.

Crystals Selection Notes

Select this component when a standard through-hole quartz crystal is required for 4 MHz applications. The HC-49/US form factor provides robust mechanical stability for industrial environments. Consider the 60 Ohm ESR value when designing the oscillator circuit to ensure proper startup conditions and sustained oscillation within the specified -40°C to +85°C operating range.

Crystals Part Context

This part belongs to the ILSI HC49US Series, which offers low-cost quartz crystals compatible with lead-free manufacturing processes. The series covers various frequencies and overtone modes, providing solutions for fiber channel, Wi-Fi, and telecom systems. The HC-49/US package is a widely adopted standard for general-purpose timing applications requiring reliable performance.

Crystals Replacement Considerations

Direct substitutes include other manufacturers' HC-49/US crystals with identical 4 MHz frequency, 18 pF load capacitance, and ±30 ppm tolerance. Verify pin compatibility and physical dimensions to ensure interchangeability without PCB modifications.