18QHTF21-13.440-PD

Overview

The 18QHTF21-13.440-PD is a standard crystal oscillator (XO) manufactured by Mercury Electronics Ind. Co., Ltd. It operates at a nominal frequency of 13.44 MHz and utilizes LVCMOS output logic levels. The device is designed for surface mount applications, featuring a compact 4-SMD, No Lead package configuration suitable for automated assembly processes. It supports a supply voltage range that typically includes 3.3V operation, with specific variants available for other voltages. The component offers an operating temperature range of -40°C to +85°C, ensuring reliability in industrial environments. Frequency stability is specified at ±50ppm over the full temperature range, providing precise timing signals for digital circuits.

Feature Summary

• LVCMOS output interface compatible with standard digital logic families
• Surface mount 4-SMD no lead package for space-constrained designs
• Industrial temperature range operation from -40°C to +85°C
• Standard crystal oscillator functionality with power down capability

Applications

• General purpose clock generation for microprocessors and microcontrollers
• Timing reference for communication interfaces such as UART and SPI
• Clock source for digital signal processing units
• System timing in industrial control equipment

Procurement Notes

Verify the exact supply voltage requirement for your specific application variant, as the 18QHTF21 series may offer different voltage options. Confirm the frequency tolerance specification matches your system requirements, noting that ±50ppm is common but not universal across all suffixes. Ensure the PCB footprint aligns with the 4-SMD no lead package dimensions provided in the official datasheet. Check for any specific handling instructions regarding electrostatic discharge sensitivity during assembly.

Selection Notes

Select this component when a low-cost, standard frequency XO is required for non-critical timing applications. The LVCMOS output simplifies interfacing with 3.3V or 1.8V logic systems without additional level shifting. Consider the ±50ppm stability limit; if tighter jitter or phase noise performance is needed, a TCXO or VCXO variant might be more appropriate. The wide operating temperature range makes it suitable for harsh environments where standard commercial grade parts would fail.

Part Context

This part belongs to the 18QHTF21 series of surface mount crystal oscillators from Mercury Electronics. The series is characterized by small form factors and standard output logic levels. Similar parts in the series include frequencies like 8MHz, 13.44MHz, 18.1059MHz, 50.44MHz, and 51.2MHz, all sharing the same physical package and general electrical characteristics. The 'PD' suffix typically indicates a specific pinout or packaging variation within the manufacturer's lineup.

Replacement Considerations

Direct replacements must match the 13.44 MHz frequency, LVCMOS output, 4-SMD no lead package, and ±50ppm stability. Verify voltage compatibility, as some competitors may only offer 3.3V or 1.8V versions. Cross-reference the pinout diagram carefully, as SMD oscillator pin assignments can vary between manufacturers even for identical packages.