QT49S-7.680MBBK-T

Overview

The QT49S-7.680MBBK-T is a MHz crystal manufactured by QST, operating at a nominal frequency of 7.68 MHz with a frequency stability and tolerance of ±50ppm. It features a load capacitance of 20pF and an equivalent series resistance (ESR) of 80 Ohms. The component utilizes the HC-49/US package, measuring 11.40mm in length, 4.80mm in width, and 4.10mm in maximum height. Designed for surface mount installation, it supports fundamental mode operation and functions within a temperature range of -20°C to +70°C.

Feature Summary

• Fundamental mode quartz crystal oscillator
• HC-49/US surface mount package configuration
• ±50ppm frequency stability specification

Applications

• General purpose clock signal generation
• Microcontroller system timing references
• Digital circuit frequency standards

Procurement Notes

Verify the specific ESR value against design requirements, as sources indicate 80 Ohms for this variant. Confirm RoHS3 compliance status prior to integration. Ensure the HC-49/US footprint matches the PCB layout constraints. Cross-reference the manufacturer datasheet for any recent product change notices affecting pinout or material composition.

Selection Notes

Select this component when a 7.68 MHz reference is required with moderate stability. The 20pF load capacitance must align with the oscillator circuit design. Consider the 80 Ohm ESR impact on start-up time. The wide temperature range suits industrial environments. Verify that the surface mount form factor fits the assembly process capabilities.

Part Context

This part belongs to the QT49S series of crystals from QST. It serves as a standard frequency control element for electronic circuits. The HC-49/US package is a common industry standard for through-hole and surface-mount applications. It provides reliable oscillation for digital systems requiring precise timing signals.

Replacement Considerations

Direct parameter-equivalent substitutes are not explicitly confirmed in public documentation for this exact model. Check for other QT49S variants with matching 7.68 MHz frequency, 20pF load, and compatible ESR values. Ensure any replacement maintains the HC-49/US footprint and ±50ppm stability rating.