QT49-20.000MAAJ-B

Overview

The QST QT49-20.000MAAJ-B is a quartz crystal resonator operating at a fundamental frequency of 20 MHz. It features a frequency stability and tolerance of ±30 ppm at 25°C. The component utilizes an 18 pF load capacitance and exhibits an equivalent series resistance (ESR) of 30 Ohms. Designed for through-hole mounting, it adheres to the HC-49/US package standard with physical dimensions of 11.5 mm in length, 5 mm in width, and 3.68 mm in height. The device operates within a temperature range of -40°C to +85°C.

Feature Summary

• Fundamental mode quartz crystal resonator construction
• Through-hole leaded package design for reliable board attachment
• Standardized HC-49/US mechanical form factor

Applications

• Microcontroller clock source circuits
• Communication module timing references
• General-purpose oscillator circuit integration

Procurement Notes

Verify that the target application supports through-hole assembly processes, as this component requires soldering leads rather than surface mount techniques. Confirm that the PCB layout accommodates the specific HC-49/US footprint dimensions to ensure proper mechanical fit. Ensure the driving circuitry provides appropriate power levels within the specified drive level range to prevent frequency instability or crystal damage during operation.

Selection Notes

Select this part when a standard through-hole crystal is required for 20 MHz applications. The HC-49/US package offers robust mechanical handling compared to surface mount alternatives. Consider the ±30 ppm stability requirement against system timing accuracy needs. Verify that the 18 pF load capacitance matches the oscillator circuit design parameters to achieve accurate frequency performance.

Part Context

This component belongs to the QST QT49 series of MHz crystals. The series provides various frequency options within the same HC-49/US package format. This specific model targets applications requiring a 20 MHz reference signal. The series is commonly used in consumer electronics and industrial control systems where reliable timing is essential.

Replacement Considerations

Direct substitutes must match the 20 MHz frequency, HC-49/US package, and 18 pF load capacitance. Cross-reference with other manufacturers offering identical through-hole specifications. Verify that alternative parts meet the same ±30 ppm stability and ESR requirements for circuit compatibility.