QT325S-18.432MAHE-T

Overview

The QT325S-18.432MAHE-T is a surface-mount crystal oscillator manufactured by QST, designed for precision timing applications. It operates at a fundamental frequency of 18.432 MHz with a load capacitance of 12 pF and an equivalent series resistance (ESR) of 60 Ohms. The component features a ±30 ppm frequency stability over the extended industrial temperature range of -40°C to +85°C, as indicated by the 'H' suffix in the part number. It utilizes a 4-SMD, no-lead package with dimensions of 3.2 x 2.5 x 0.7 mm, ensuring compact integration into high-density circuit boards while maintaining reliable performance under varying thermal conditions.

Feature Summary

• Compact 4-SMD no-lead package design suitable for space-constrained PCB layouts
• Extended industrial temperature operation from -40°C to +85°C
• High frequency stability of ±30 ppm across the operating range
• Fundamental mode resonance for precise clock signal generation

Applications

• Wireless networking equipment requiring stable clock references
• Embedded systems with strict timing synchronization needs
• Consumer electronics utilizing microcontroller-based architectures
• Industrial control modules operating in variable thermal environments

Procurement Notes

Verify the specific suffix codes against official QST documentation to confirm temperature range and tolerance specifications. Ensure compatibility with standard reflow soldering profiles for 4-SMD packages. Cross-reference the load capacitance requirement with the target circuit design to maintain frequency accuracy. Confirm that the 18.432 MHz output aligns with system clock requirements before finalizing procurement orders.

Selection Notes

Select this component when a 18.432 MHz reference is required with ±30 ppm stability over -40°C to +85°C. The 12 pF load capacitance must match the oscillator circuit design. Consider the 60 Ohm ESR for drive level limitations. The 3.2x2.5mm footprint dictates board space availability. Verify that the application does not require tighter tolerances than ±30 ppm or different temperature ranges.

Part Context

This part belongs to the QT325S series of surface-mount crystals from QST, characterized by small form factors and standardized electrical parameters. The series supports various frequencies and stability grades, with the MAHE-T variant specifically denoting the 18.432 MHz frequency, ±30 ppm stability, and extended temperature range capabilities within the 4-SMD package family.

Replacement Considerations

Direct substitutes include other manufacturers offering 18.432 MHz crystals in 3.2x2.5mm SMD packages with 12pF load capacitance and ±30 ppm stability over -40°C to +85°C. Verify pinout compatibility and mechanical dimensions before substitution. Ensure equivalent ESR values to prevent drive level issues in the host oscillator circuit.