18QHTF21-7.994-PD

Overview

The 18QHTF21-7.994-PD is a standard crystal oscillator manufactured by Mercury Electronics Ind. Co. Ltd. It operates at a fixed frequency of 7.994 MHz and utilizes LVCMOS output logic levels. The device is designed for surface mount applications, featuring a compact 4-SMD, No Lead package with dimensions of 2.00mm x 1.60mm. It supports a supply voltage of 1.8V and includes a power-down function for standby mode control.

Feature Summary

• Standard XO configuration with LVCMOS output interface
• Integrated power-down capability for standby mode operation
• Compact 4-SMD no-lead surface mount package design

Applications

• General clock signal generation in electronic circuits
• Timing reference for low-voltage digital systems
• Embedded devices requiring precise frequency standards

Procurement Notes

Verify the specific frequency tolerance and load capacitance requirements against your circuit design before procurement. Confirm that the 1.8V supply voltage aligns with your system's power rails. Ensure the 4-SMD package footprint matches your PCB layout constraints. Check for any specific operating temperature range limitations defined in the official datasheet to guarantee reliability under your environmental conditions.

Selection Notes

Select this component when a precise 7.994 MHz timing source is required for LVCMOS-compatible logic families. The choice is driven by the need for a low-profile surface mount solution with integrated power management features. Consider the 1.8V operating voltage as a primary constraint for compatibility with modern low-power digital architectures.

Part Context

This part belongs to the Mercury Electronics 18QHTF21 series of standard crystal oscillators. The series offers various frequency options within a consistent 4-SMD form factor. The 'PD' suffix indicates the inclusion of a power-down pin or function, distinguishing it from basic continuous-operation variants within the same physical package family.

Replacement Considerations

Direct substitutes must match the 7.994 MHz frequency, LVCMOS output, 1.8V supply, and 4-SMD package dimensions. Verify pinout compatibility and electrical characteristics before swapping manufacturers.