QT325S-38.400MEIQ-T

Overview

The QST QT325S-38.400MEIQ-T is a quartz crystal resonator operating at a fundamental frequency of 38.4 MHz. It features a frequency stability of ±10 ppm at 25°C and ±20 ppm over the temperature range of -40°C to +85°C. The component utilizes a load capacitance of 10 pF and an equivalent series resistance (ESR) of 50 Ohms maximum. It is housed in a compact 4-SMD, No Lead package with dimensions of 3.2 x 2.5 x 0.7 mm, designed for surface-mount assembly.

Feature Summary

• Compact 3.2x2.5mm SMD footprint for space-constrained designs
• High frequency stability suitable for precision timing applications
• Robust performance across extended industrial temperature ranges

Applications

• Embedded communication systems requiring precise clock signals
• Microcontroller unit (MCU) clock sources
• Real-time clock (RTC) circuits
• Digital signal processing (DSP) interfaces

Procurement Notes

Verify the complete part number against official QST documentation to ensure correct suffix alignment. Confirm that the 'I' suffix corresponds to the specified ±20 ppm stability over the -40°C to +85°C range. Cross-reference the load capacitance and ESR values with the target circuit design requirements before procurement to avoid compatibility issues.

Selection Notes

Select this component when a 38.4 MHz reference is required with tight stability constraints in harsh environments. Ensure the PCB layout supports the 4-SMD no-lead package geometry. Compare against alternative frequencies if system architecture allows flexibility, but prioritize this specific model for its balance of size and thermal stability.

Part Context

This part belongs to the QT325S family of ultra-small quartz crystals from QST. The family offers various frequency options within the same mechanical envelope. The MEIQ suffix denotes specific electrical characteristics including load capacitance and temperature stability, differentiating it from other variants like MEEQ or MAAC which may have different stability ratings or temperature ranges.

Replacement Considerations

Direct substitutes must match the 38.4 MHz frequency, 10pF load capacitance, and 3.2x2.5mm package. Verify equivalent ESR limits and stability grades. Generic replacements may require re-validation of oscillator circuit parameters due to potential differences in motional capacitance and drive level sensitivity.