QT49S-30.000MEEJ-T

Overview

The QT49S-30.000MEEJ-T is a surface-mount quartz crystal resonator manufactured by QST, designed for precise frequency generation in electronic circuits. It operates at a nominal frequency of 30 MHz with a stability tolerance of ±10 ppm at 25°C and ±10 ppm across the temperature range of -20°C to +70°C. The component features a load capacitance of 18 pF and an equivalent series resistance (ESR) of 30 Ohms. It utilizes the HC-49/US form factor adapted for surface mount technology, with physical dimensions of 12.7 x 4.8 x 3.8 mm. This SMD configuration allows for automated assembly processes while maintaining the reliability associated with standard HC-49 crystals.

Feature Summary

• Surface mount design compatible with automated pick-and-place manufacturing processes
• High frequency stability within specified industrial temperature ranges
• Standardized HC-49/US footprint adapted for PCB integration

Applications

• Clock signal generation for microcontrollers and digital logic circuits
• Frequency reference sources for communication modules operating at 30 MHz
• Timing components in consumer electronics requiring stable oscillation

Procurement Notes

Verify that the specific suffix 'MEEJ' corresponds to the required surface mount package variant and soldering profile. Confirm that the ±10 ppm stability meets the system timing requirements. Ensure the 18 pF load capacitance matches the oscillator circuit design specifications. Check for RoHS compliance status if environmental regulations apply to the final product assembly.

Selection Notes

Select this component when a 30 MHz surface-mount crystal is required instead of through-hole alternatives. Consider the 30 Ohm ESR value to ensure compatibility with the driving circuit's power constraints. Evaluate the thermal stability range against the operational environment of the target device. Compare physical dimensions against available PCB real estate to confirm fitment without mechanical interference.

Part Context

This part belongs to the QT49S series of quartz crystals from QST, which offers various frequency options in a compact surface-mount format. The series provides alternatives to traditional leaded HC-49/U crystals, facilitating modern PCB layouts. Other variants in the family include different frequencies such as 16 MHz or 13.56 MHz, sharing similar electrical characteristics but differing in resonant properties.

Replacement Considerations

Direct substitutes may include other manufacturers' 30 MHz SMD crystals with identical 18 pF load capacitance and comparable ESR values. Verify pinout compatibility and mounting hole alignment if replacing with generic HC-49S equivalents. Ensure frequency tolerance matches the original ±10 ppm specification to maintain system timing integrity.