XTL721-S999-437

Crystals Overview

The Siward XTL721-S999-437 is a surface-mount tuning fork crystal resonator designed for precision timing applications. It operates at a fundamental frequency of 32.768 kHz with an equivalent series resistance (ESR) of 70 kOhms. The component supports an operating temperature range from -40°C to 125°C and holds AEC-Q200 ratings, indicating suitability for automotive environments. Its physical dimensions are 3.20mm in length by 1.50mm in width, housed in a 2-SMD, no-lead package.

Crystals Feature Summary

• AEC-Q200 qualified for automotive reliability standards
• High stability tuning fork design for low-power clocking
• Wide industrial temperature operation capability

Crystals Applications

• Automotive electronic systems requiring precise timekeeping
• Industrial equipment needing extended temperature tolerance
• Real-time clock circuits in consumer electronics

Crystals Procurement Notes

Verify the specific suffix '437' against official SIWARD documentation to confirm exact ESR and tolerance specifications. Ensure compatibility with the target circuit's load capacitance requirements. Confirm that the AEC-Q200 rating aligns with the end-product's automotive qualification needs. Request batch-specific test reports if required for quality assurance protocols.

Crystals Selection Notes

Select this component when automotive-grade reliability and wide temperature operation are mandatory. The high ESR value suggests it is optimized for specific oscillator circuit designs rather than general-purpose use. Consider the 3215 package size for space-constrained PCB layouts. Validate the fundamental operating mode against the host microcontroller's clock input specifications.

Crystals Part Context

This part belongs to the XTL721 series of tuning fork crystals manufactured by Siward Crystal Technology Co., Ltd. The series focuses on quartz frequency control elements utilizing piezoelectric effects. The model number indicates specific dimensional and electrical characteristics within the company's product line for surface-mount applications.

Crystals Replacement Considerations

Direct substitutes include other AEC-Q200 qualified 32.768 kHz tuning fork crystals in the 3215 package. Verify equivalent ESR values to ensure oscillator startup reliability. Check for identical temperature ranges and load capacitance requirements before substitution.