XTL721-S999-429

Crystals Overview

The Siward XTL721-S999-429 is a surface-mount tuning fork crystal designed for precision timing applications. It operates at a nominal frequency of 32.768 kHz, which facilitates accurate timekeeping through binary division. The component features a load capacitance of 6 pF and maintains a normal temperature frequency tolerance of ±20 ppm. It exhibits an equivalent series resistance (ESR) of 70 kΩ and functions within an operating temperature range of -40°C to +85°C. The device utilizes a two-terminal no-lead SMD package.

Crystals Feature Summary

• Precision timing capability via standard 32.768 kHz frequency
• Low power consumption suitable for battery-operated devices
• Robust performance across extended industrial temperature ranges

Crystals Applications

• Real-time clock circuits in consumer electronics
• Wristwatches and portable timekeeping devices
• Embedded systems requiring stable system clocks

Crystals Procurement Notes

Verify the specific load capacitance requirement against the target circuit design, as this variant specifies 6 pF rather than the common 12.5 pF. Confirm that the application environment remains within the specified -40°C to +85°C operational limits to ensure frequency stability. Cross-reference the ESR value with oscillator circuit specifications to guarantee reliable startup conditions.

Crystals Selection Notes

Select this component when a compact surface-mount solution is required for low-frequency timing references. The 6 pF load capacitance necessitates careful matching with the host oscillator's internal capacitors to achieve the specified ±20 ppm accuracy. Consider the 70 kΩ ESR limit when designing the drive level to prevent overdriving the crystal element.

Crystals Part Context

This part belongs to the Siward XTL721 series of tuning fork crystals, optimized for space-constrained electronic designs. The model suffix typically denotes specific electrical characteristics such as load capacitance and tolerance within the product family. These components are engineered to provide stable oscillation for microcontrollers and RTC modules in modern portable hardware.

Crystals Replacement Considerations

Direct substitutes include other 32.768 kHz SMD crystals with identical 6 pF load capacitance and ±20 ppm tolerance. Ensure replacement parts support the same 70 kΩ ESR maximum and operate within the -40°C to +85°C range to maintain circuit compatibility.