QT49S-3.579545MAHJ-T

Overview

The QT49S-3.579545MAHJ-T is a surface-mount quartz crystal resonator manufactured by QST, belonging to the QT49S series. It operates at a fundamental frequency of 3.579545 MHz and utilizes an HC-49/US package style with dimensions of 12.7mm x 4.8mm x 3.8mm. The component features a load capacitance of 18pF, with both frequency stability and tolerance rated at ±30ppm. Its equivalent series resistance (ESR) is specified as 200 Ohms. This device is designed for reliable clock signal generation in electronic circuits requiring precise timing.

Feature Summary

• Surface mount construction for automated assembly
• HC-49/US form factor compatible footprint
• Fundamental mode quartz resonance
• Standard 18pF load capacitance configuration

Applications

• Microcontroller clock sources
• Communication interface timing
• Digital logic circuit synchronization
• Embedded system oscillators

Procurement Notes

Verify the specific suffix 'AHJ-T' against official QST documentation to confirm tape-and-reel packaging and lead-free status. Ensure the ordering code matches the required quantity format. Cross-reference the manufacturer's latest datasheet for any updates on environmental compliance or RoHS directives before finalizing procurement orders.

Selection Notes

Select this component when a 3.579545 MHz reference is required for NTSC video processing or specific serial communication standards. The ±30ppm stability suits general-purpose digital applications rather than high-precision RF systems. Consider the 200 Ohm ESR value for oscillator circuit design compatibility. Verify that the operating temperature range meets the target application's thermal requirements.

Part Context

This part belongs to the QT49S series of surface-mount crystals from QST. The series offers various frequencies within the HC-49/US footprint. Other variants include different frequencies like 16MHz or 24MHz. The model number encodes the frequency and package type. This specific variant targets cost-sensitive mass production environments.

Replacement Considerations

Direct substitutes may include other manufacturers offering HC-49SMD crystals at 3.579545 MHz with 18pF load capacitance. Verify pin compatibility and electrical parameters such as ESR and stability. Check if alternative packages like HC-49U are acceptable for the PCB layout. Ensure the replacement maintains the same fundamental frequency mode.