QT49S-7.680MAHJ-T

Overview

The QT49S-7.680MAHJ-T is a surface-mount quartz crystal oscillator manufactured by QST, operating at a fundamental frequency of 7.68 MHz. It features a tolerance and stability of ±30 ppm across the specified temperature range. The component utilizes an HC-49/US package form factor with surface mount technology, measuring 12.7 mm in length, 4.8 mm in width, and 3.8 mm in height. It has a load capacitance of 18 pF and an equivalent series resistance (ESR) of 80 Ohms. The device is RoHS compliant and designed for integration into electronic circuits requiring precise timing references.

Feature Summary

• Surface-mount construction utilizing HC-49/US package dimensions for compact PCB integration
• Fundamental mode quartz resonator providing stable oscillation at 7.68 MHz
• ±30 ppm frequency tolerance ensuring reliable timing accuracy in standard applications

Applications

• Microcontroller clock sources
• Communication interface timing circuits
• Digital signal processing systems

Procurement Notes

Verify the specific manufacturer designation, as some listings associate this part number with TXC rather than QST. Confirm the exact package style matches the HC-49/US SMD footprint dimensions of 12.7x4.8x3.8mm. Ensure the load capacitance requirement of the target circuit aligns with the 18pF specification to maintain frequency accuracy. Check RoHS compliance status if environmental regulations are mandatory for the end product.

Selection Notes

Select this component when a 7.68 MHz reference is required for digital logic or communication protocols. The ±30 ppm tolerance suits general-purpose applications where high precision is not critical. Consider the 80 Ohm ESR value for oscillator circuit design compatibility. The surface-mount format facilitates automated assembly processes compared to through-hole alternatives.

Part Context

This part belongs to the QT49S series of quartz crystals, which includes various frequencies such as 16.000 MHz variants. The series typically offers HC-49/US form factors adapted for surface mounting. These components serve as passive timing elements in electronic assemblies, replacing older through-hole designs to save board space.

Replacement Considerations

Cross-reference with other manufacturers offering 7.68 MHz SMD crystals with identical 18pF load capacitance and ±30 ppm tolerance. Verify that substitute parts match the 12.7x4.8x3.8mm physical envelope to ensure mechanical fit. Confirm electrical parameters like ESR remain within acceptable limits for the host oscillator circuit.