18QHTF21-7.9959-PD

Overview

The 18QHTF21-7.9959-PD is a standard crystal oscillator (XO) manufactured by Mercury Electronics Ind. Co. Ltd. It operates at a frequency of 7.9959 MHz and utilizes LVCMOS output logic. The device is designed for a supply voltage of 1.8V and features a standby or power-down function to reduce consumption during inactive periods. It is housed in a compact 4-SMD, no-lead package with dimensions of 2.0mm x 1.6mm.

Feature Summary

• Supports low-voltage operation at 1.8V
• Includes standby mode for power management
• Utilizes LVCMOS output interface

Applications

• General clock signal generation
• Embedded system timing references
• Consumer electronics circuits

Procurement Notes

Verify the specific frequency tolerance and load capacitance requirements against the target circuit design before procurement. Confirm that the 1.8V supply voltage aligns with the system's power rails. Ensure the PCB footprint matches the 4-SMD no-lead package dimensions of 2.0x1.6mm. Check for any specific reflow soldering profile recommendations provided by the manufacturer to ensure joint integrity.

Selection Notes

Select this component when a precise 7.9959 MHz clock source is required for low-power applications. The choice is driven by the need for a small form factor and integrated power-down capability. Consider the LVCMOS compatibility with downstream digital logic inputs. Evaluate the operating temperature range specifications to ensure reliability under expected environmental conditions.

Part Context

This part belongs to the 18QHTF21 series from Mercury Electronics, which focuses on miniature surface-mount oscillators. The series typically offers various frequencies within a standardized 2.0x1.6mm package. The 'PD' suffix indicates the inclusion of a power-down control feature, distinguishing it from continuous-operation variants in the same family.

Replacement Considerations

Direct substitutes may include other 7.9959 MHz XO components in 4-SMD packages with compatible 1.8V LVCMOS outputs. Verify pinout compatibility and electrical characteristics such as phase noise and jitter before substitution.