HC49US-FF5F18-27.000MHZ

Crystals Overview

The ILSI HC49US-FF5F18-27.000MHZ is a parallel fundamental quartz crystal operating at a nominal frequency of 27 MHz. It features a ±30 ppm frequency tolerance and stability, with an 18 pF load capacitance. The component utilizes the HC-49/US surface mount package, measuring approximately 11.4 mm in length and 4.7 mm in width. It exhibits an equivalent series resistance (ESR) of 30 Ohms and supports a drive level of 1 mW. The device operates within a temperature range of -40°C to +85°C and is RoHS compliant.

Crystals Feature Summary

• Fundamental parallel resonance mode for stable clock generation
• Surface mount HC-49/US package design for automated assembly
• AT-cut quartz construction ensuring long-term aging stability
• Lead-free processing compatibility and RoHS compliance

Crystals Applications

• T1/E1 and T3/E3 system clock synchronization
• SONET/SDH network interface timing
• Fiber channel server and storage controller clocks
• General-purpose microprocessor and microcontroller oscillator circuits

Crystals Procurement Notes

Verify the specific suffix 'FF5F18' matches the required load capacitance and tolerance specifications for the target circuit design. Confirm that the HC-49/US surface mount footprint aligns with the PCB layout constraints. Ensure the operating temperature range of -40°C to +85°C meets the environmental requirements of the final application. Check for any recent manufacturing status updates as some variants may be obsolete.

Crystals Selection Notes

Select this component when a 27 MHz reference signal is required with moderate stability needs. The 30 ppm tolerance is suitable for standard communication protocols but may not suffice for high-precision timing applications requiring tighter tolerances. Consider the 30 Ohm ESR value to ensure the oscillator circuit can sustain oscillation reliably. The surface mount format is preferred for compact designs where through-hole mounting is not feasible.

Crystals Part Context

This part belongs to the ILSI HC49US series of quartz crystals, which are widely used in digital electronics for providing precise timing references. The HC-49/US package is a standard industry form factor, allowing for broad compatibility across various manufacturers' components. These crystals are typically employed in communication systems, computing hardware, and industrial control equipment where reliable frequency generation is critical for data integrity and synchronization.

Crystals Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation. Verify if other ILSI models within the HC49US series with identical electrical parameters can serve as direct replacements. Cross-reference with other manufacturers offering HC-49/US packages at 27 MHz with 18 pF load capacitance and ±30 ppm tolerance.