18QHTF21-77.850-PD

Overview

The 18QHTF21-77.850-PD is a standard crystal oscillator manufactured by Mercury Electronics Ind. Co. Ltd. It operates at a nominal frequency of 77.85 MHz with an LVCMOS output logic level. The device requires a 1.8V supply voltage and features a standby function for power down control. It is housed in a compact 4-SMD, no lead package with dimensions of 2.0mm x 1.6mm. The unit supports an operating temperature range from -40°C to 85°C and maintains a frequency stability of ±50ppm.

Feature Summary

• Supports standby mode for power management
• Compact surface-mount package design
• 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. Ensure the 1.8V supply rail is stable within the specified operating temperature range to maintain the stated ±50ppm frequency stability. Confirm that the PCB footprint matches the 4-SMD no-lead package dimensions to avoid assembly issues during manufacturing.

Selection Notes

Select this component when a low-voltage 1.8V operation is required alongside a small form factor. The LVCMOS output is suitable for direct interfacing with digital logic families. Consider the ±50ppm stability limit for applications requiring precise timing synchronization. The wide industrial temperature range makes it appropriate for environments subject to thermal variation.

Part Context

This model belongs to the 18QHTF21 series of surface-mount oscillators from Mercury Electronics. The series offers various frequency options within a standardized 2.0x1.6mm package. The 'PD' suffix indicates the inclusion of a power-down pin or functionality. Mercury Electronics utilizes quartz crystal technology to ensure long-term reliability and frequency accuracy across the product line.

Replacement Considerations

Compatible substitutes include other 1.8V LVCMOS oscillators in 4-SMD packages with similar frequency and stability ratings. Verify pinout compatibility and thermal characteristics when cross-referencing with alternative manufacturers.