HC49USM-FF5F18-27.000MHZ

Crystals Overview

The ILSI HC49USM-FF5F18-27.000MHZ is a surface-mount quartz crystal resonator operating at a nominal frequency of 27.000 MHz. It utilizes the HC-49/US package with dimensions of 13.3 mm in length, 4.7 mm in width, and a maximum height of 4.5 mm. The component features a load capacitance of 18 pF and offers a frequency tolerance and stability of ±30 ppm. Designed for fundamental mode operation, it supports an operating temperature range from -40°C to +85°C and is compatible with lead-free processing standards.

Crystals Feature Summary

• Surface-mount construction within the standard HC-49/US metal package
• Grounded package design intended to minimize electromagnetic interference
• Compliant with RoHS directives and lead-free manufacturing processes

Crystals Applications

• SONET/SDH system clocking
• T1/E1 and T3/E3 network interfaces
• 802.11 Wi-Fi infrastructure equipment
• Fibre Channel server and storage systems

Crystals Procurement Notes

Verify that the specific suffix FF5F18 corresponds to the required 18 pF load capacitance and ±30 ppm tolerance specifications. Confirm the package orientation matches the target PCB footprint, as HC-49/US components have defined pin configurations. Ensure the selected variant meets the thermal requirements for the intended operating environment, specifically the -40°C to +85°C range. Cross-reference the manufacturer's latest datasheet to confirm compliance with current environmental regulations and material declarations before finalizing procurement orders.

Crystals Selection Notes

Select this component when a standard surface-mount crystal is required for 27 MHz applications with moderate stability needs. The HC-49/US form factor provides a robust mechanical solution suitable for automated assembly processes. Consider the 18 pF load capacitance requirement to ensure proper oscillator circuit tuning. This series is appropriate for general-purpose digital circuits where cost-effectiveness and standard reliability are prioritized over ultra-high precision or extreme miniaturization.

Crystals Part Context

This part belongs to the ILSI HC49USM series, which encompasses various surface-mount quartz crystals designed for high-volume consumer and industrial electronics. The series is characterized by its compatibility with standard reflow soldering profiles and its widespread adoption in telecommunications and computing hardware. The HC-49/US package remains a common industry standard for through-hole and surface-mount implementations requiring reliable frequency generation.

Crystals Replacement Considerations

Direct substitutes include other manufacturers' HC-49/US crystals with identical 27.000 MHz frequency, 18 pF load capacitance, and ±30 ppm tolerance. Verify that alternative parts maintain the same physical dimensions and pinout to ensure mechanical compatibility without PCB redesign.