QT325S-25.000MABK-T

Overview

The QT325S-25.000MABK-T is a surface-mount quartz crystal oscillator manufactured by QST, designed for precise frequency generation in electronic circuits. It operates at a fundamental frequency of 25 MHz and utilizes a 4-SMD, no-lead package with dimensions of 3.2 x 2.5 x 0.7 mm. The component features a load capacitance of 18 pF and an equivalent series resistance (ESR) of 50 Ohms. Frequency stability is specified at ±30 ppm over the operating temperature range of -20°C to +70°C, ensuring reliable performance in standard commercial applications.

Feature Summary

• Provides stable 25 MHz oscillation for digital clocking and timing reference
• Utilizes compact 4-SMD no-lead surface mount packaging for automated assembly
• Maintains frequency accuracy within ±30 ppm across the commercial temperature range

Applications

• Microcontroller clock input circuits
• Communication module timing references
• Digital signal processing systems

Procurement Notes

Verify the specific suffix 'BK' against official QST documentation to confirm exact tolerance and temperature specifications, as suffixes define critical electrical parameters. Ensure compatibility with reflow soldering profiles suitable for 4-SMD packages. Confirm availability through authorized distributors, as supply status may vary. Cross-reference the load capacitance requirement with the target circuit design to ensure proper frequency loading.

Selection Notes

Select this component when a 25 MHz frequency source is required for space-constrained designs utilizing SMD assembly. The 18 pF load capacitance must match the external capacitors in the oscillator circuit to achieve the specified frequency accuracy. Consider the ±30 ppm stability limit for applications requiring moderate precision. Evaluate the 50 Ohm ESR against the driving circuit capabilities to prevent overdriving or startup failures.

Part Context

This part belongs to the QT325S series of quartz crystals from QST, characterized by small form factor and leadless construction. The series offers various frequency options and stability grades defined by alphanumeric suffixes. The QT325S line is engineered for high-volume manufacturing processes, providing consistent performance for consumer electronics and industrial control systems requiring reliable timing signals.

Replacement Considerations

Direct substitutes include other 25 MHz crystals in 3.2x2.5mm 4-SMD packages with matching 18pF load capacitance and similar stability ratings. Verify pinout compatibility and mechanical height constraints before substitution. Equivalent parts from other manufacturers must meet the same electrical specifications to ensure circuit functionality without modification.