QTT252-26.000MCS-T

Overview

The QTT252-26.000MCS-T is a Voltage-Controlled Temperature Compensated Crystal Oscillator (VCTCXO) manufactured by QST, housed in a compact 2.5mm x 2.0mm surface-mount ceramic package. It operates at a nominal frequency of 26.000 MHz with a clipped sine wave output format. The device supports dual supply voltages of 2.5V and 3.3V, featuring an external control voltage input for frequency adjustment. Key electrical specifications include a frequency stability of ±1.0 ppm over the industrial temperature range of -40°C to +85°C and a maximum aging rate of ±1.0 ppm per year after the first year of operation.

Feature Summary

• Integrates VCTCXO functionality within a miniature 2520 ceramic package for space-constrained designs
• Provides precise frequency control via external analog control voltage interface
• Ensures high thermal stability across wide industrial operating temperatures
• Compatible with standard low-voltage digital logic systems

Applications

• Bluetooth Low Energy (BLE) modules requiring stable clock sources
• GPS navigation receivers needing precise timing synchronization
• Wireless communication devices utilizing 26 MHz reference frequencies
• IoT sensors demanding low power consumption and small form factors

Procurement Notes

Verify the specific suffix 'C' against the manufacturer's official datasheet to confirm the exact frequency tolerance and control voltage range, as these parameters vary significantly across the QTT252 series. Ensure that the design accommodates the required decoupling capacitor on the supply pin as mandated by the circuit requirements. Confirm that the selected variant matches the intended supply voltage of either 2.5V or 3.3V for proper operation.

Selection Notes

Select this component when a highly stable 26 MHz clock is required in a minimal footprint. The VCTCXO architecture allows for fine-tuning the output frequency to compensate for system-level drift, which is critical for maintaining link integrity in wireless protocols. Compare the control voltage sensitivity and pull range against the microcontroller's DAC capabilities to ensure adequate calibration headroom for the final application environment.

Part Context

This oscillator belongs to the QTT252 family, a line of surface-mount VCTCXOs designed for portable electronics. The series offers various frequency options and tolerance grades within the same 2520 package, allowing designers to maintain consistent board layouts while adjusting for different RF performance requirements. It serves as a direct replacement for larger through-hole or standard SMD TCXOs where space is at a premium.

Replacement Considerations

Direct substitutes within the same package and specification may include other part numbers from the QTT252 series such as QTT252-26.000MBN-T or QTT252-26.000MDG-T, provided they match the specific frequency tolerance and control voltage characteristics. Always cross-reference the mechanical dimensions and pinout compatibility before substitution.