QT49-12.000MEEJ-B

Overview

The QT49-12.000MEEJ-B is a 12 MHz quartz crystal resonator manufactured by QST, belonging to the QT49 series. It features a frequency stability and tolerance of ±10 ppm at 25°C. The component utilizes an 18 pF load capacitance and exhibits an equivalent series resistance (ESR) of 40 Ohms. Designed for through-hole mounting, it is housed in an HC-49/US package with dimensions of 11.50mm x 5.00mm x 3.68mm. The device operates within a temperature range of -20°C to +70°C and complies with RoHS3 standards.

Feature Summary

• Provides high frequency stability of ±10 ppm for precise timing applications
• Utilizes standard HC-49/US through-hole package for easy integration
• Operates reliably across extended industrial temperature ranges

Applications

• Microcontroller clock sources
• Communication equipment timing circuits
• Industrial control systems

Procurement Notes

Verify that the selected component matches the required HC-49/US form factor and through-hole mounting style. Confirm that the ±10 ppm stability specification meets the system's timing accuracy requirements. Ensure the operating temperature range of -20°C to +70°C aligns with the environmental conditions of the final application. Check for RoHS3 compliance if restricted substances are a concern.

Selection Notes

Select this crystal when a standard through-hole footprint is necessary for PCB assembly or prototyping. The ±10 ppm tolerance offers better precision than basic ±30 ppm variants, suitable for applications requiring stable clock signals. Consider the 40 Ohm ESR value to ensure compatibility with the oscillator circuit's drive level specifications. The HC-49/US size provides mechanical robustness compared to smaller surface-mount alternatives.

Part Context

This part belongs to the QT49 series of MHz crystals from QST, designed for general-purpose timing applications. The series includes various frequency options and tolerance levels, with the 'E' suffix indicating the ±10 ppm stability grade. The HC-49/US package is a widely used standard in electronics manufacturing, ensuring broad availability of compatible sockets and mounting solutions across different industries.

Replacement Considerations

Direct substitutes must match the 12 MHz frequency, ±10 ppm stability, 18 pF load capacitance, and HC-49/US package. Verify that alternative components support the same -20°C to +70°C operating range and similar ESR values to maintain circuit performance without modification.