HC49US-FF3F18-12.000MHZ

Crystals Overview

The HC49US-FF3F18-12.000MHZ is a parallel fundamental quartz crystal manufactured by ILSI America, designed for surface mount applications within the HC49US series. It operates at a nominal frequency of 12 MHz with a frequency tolerance and stability of ±30 ppm. The component features a load capacitance of 18 pF and an equivalent series resistance (ESR) of 60 Ohms. Physical dimensions are specified as 11.40 mm in length, 4.73 mm in width, and a maximum height of 4.50 mm. It supports a base harmonic operating mode and is rated for a temperature range of -40°C to +85°C.

Crystals Feature Summary

• Provides stable oscillation at 12 MHz with ±30 ppm frequency tolerance for precise timing control.
• Utilizes AT-cut quartz technology to ensure low aging rates and long-term reliability.
• Features a hermetically sealed metal package that prevents moisture absorption and eliminates moisture sensitivity level requirements.

Crystals Applications

• Clock source for microcontrollers and microprocessors
• Reference clock for high-precision TCXO systems
• Communication equipment and modems
• Computer peripherals

Crystals Procurement Notes

This specific part number is officially classified as obsolete and is no longer manufactured by ILSI America. Procurement efforts should focus on verifying stock availability through authorized distributors or secondary market suppliers. Buyers must confirm the authenticity and storage history of available units due to the discontinuation status. Alternative sourcing strategies or direct engagement with the manufacturer for last-time buy information may be necessary to secure sufficient quantities for production needs.

Crystals Selection Notes

When selecting this component, verify compatibility with the target circuit's load capacitance requirements, specifically the 18 pF specification. Ensure the design accommodates the 60 Ohm ESR value to guarantee reliable startup conditions. The HC-49/US surface mount package requires appropriate PCB footprint design. Given the obsolete status, engineers should evaluate replacement options from the same family or cross-reference with current ILSI offerings that match the 12 MHz frequency and ±30 ppm tolerance constraints.

Crystals Part Context

The HC49US series represents a line of surface mount quartz crystals known for their robust metal sealing and cost-effectiveness compared to other brands. This model belongs to the FF3F variant family, indicating specific terminal and packaging characteristics. The HC-49/US form factor is widely adopted in consumer electronics and industrial applications due to its compact size and ease of integration into standard assembly processes without requiring significant design modifications.

Crystals Replacement Considerations

As the HC49US-FF3F18-12.000MHZ is obsolete, consider substituting with active ILSI parts such as the HC49USM-FF5F18-12.000MHZ if available, ensuring identical electrical parameters including 12 MHz frequency, 18 pF load capacitance, and ±30 ppm tolerance. Verify that any substitute maintains the same physical dimensions and mounting style to fit existing PCB layouts without redesign.