HC49USM-FF5F18-18.4320MHZ

Crystals Overview

The ILSI HC49USM-FF5F18-18.4320MHZ is a surface-mount quartz crystal resonator operating at a nominal frequency of 18.432 MHz. It utilizes the HC-49/US package with dimensions of 13.3 mm x 4.7 mm and a maximum height of 4.50 mm. The component features a load capacitance of 18 pF, a frequency tolerance of ±30 ppm, and an equivalent series resistance (ESR) of 40 Ohms. It supports fundamental mode operation within a temperature range of -40°C to +85°C.

Crystals Feature Summary

• Surface-mount construction in standard HC-49/US metal package
• Fundamental resonance mode for stable clock generation
• RoHS compliant and lead-free processing compatible

Crystals Applications

• Microcontroller clock sources
• Communication interface timing circuits
• General-purpose digital system oscillators

Crystals Procurement Notes

Verify the specific manufacturer designation upon ordering, as the part number appears in distributor catalogs under both ILSI and Abracon branding. Confirm that the requested unit matches the HC-49/US SMD form factor and 18.432 MHz frequency specification. Ensure compatibility with automated pick-and-place equipment due to the surface-mount design. Check for any recent product discontinuation notices or lifecycle changes associated with this specific part number variant.

Crystals Selection Notes

Select this component when a standard 18.432 MHz reference is required for serial communication protocols such as RS-232 or UART. The 18 pF load capacitance must match the oscillator circuit design requirements. Consider the 40 Ohm ESR value for drive level sensitivity. The wide operating temperature range suits industrial applications. Verify pin compatibility if replacing through-hole variants with this SMD version.

Crystals Part Context

This part belongs to the HC49USM series, which represents surface-mount versions of the traditional HC-49/U through-hole crystals. The series provides a compact footprint suitable for high-density PCB layouts while maintaining the electrical performance characteristics of fundamental mode quartz resonators. It serves as a direct replacement for larger through-hole components in space-constrained designs.

Crystals Replacement Considerations

Direct substitutes include other manufacturers' HC-49/US SMD crystals with identical 18.432 MHz frequency, 18 pF load capacitance, and similar ESR values. Cross-reference specifications for mechanical height and pad layout compatibility. Note that some distributors list this part under different brand names, requiring verification of the actual source manufacturer.