Würth and their IQD Frequency Products division provide a range of highly robust hermetically-sealed oscillators, making getting reliable oscillator performance easy.

Both Würth and IQD have long extended their range outside classic quartzes. Hermetically sealed products such as the LFSPXO020088Bulk and 831018545 discussed in this article provide a range of benefits to circuit designers.

Most importantly, their hermetic design leads to robustness against ambient events. This permits Würth to create an average frequency stability of ±50.00ppm, which furthermore is said to age per ±3ppm per year max.

In terms of phase noise, the products manage impressive results:

Phase Noise @125MHz (typical):
10Hz -54dBc
100Hz -92dBc
1kHz -130dBc
10kHz -149dBc
100kHz -159dBc
1MHz -163dBc
RMS Phase Jitter @125MHz: 52fs typical

Straightforward Application Design

Traditional quartz oscillators require external oscillator components to output a square waveform. Thanks to the integrated drive circuit, the system works as shown in the application schematic.

Integrated signal conditioning ensures that the output signal is according to HCMOS standards. The rise and fall time is in the range of only eight nanoseconds, while the duty cycle of 45/55 tends to satisfy the most demanding microcontroller applications. The Enable input can be used to modify oscillator behavior. If a zero logic level is applied to the pad, the oscillator ceases to oscillate, waiting for the return of one.

The housing - Würth refers to it as CFPS-73 - is shared among a wide variety of parts. The same oscillator design on the printed circuit board can be recycled to create multiple different versions - in most cases, the frequency span ranges from 4 MHz to above 100 MHz.

Furthermore, the housing is comfortably solderable, which means that PCB assembly can be comfortably performed both with a pick-and-place machine and manually.

Different Product Codes for Various Temperature Ranges

Coming in a hermetically sealed environment, the LFSPXO family is ideal for all kinds of oscillators that have to work in challenging thermal and environmental conditions. Würth provides two different classes: the LFSPXO020088Bulk covers the temperature range of -40°C ~ 85°C, while its colleague 831018545 handles the 0.00 to 70.00°C temperature range.

Conclusion

Getting oscillator circuits to work is interesting - the venerable book ‘Art of Electronics‘ dedicates multiple chapters to this topic. Fortunately, the modern semiconductor industry provides a comfortable and easy-to-use alternative. Dropping an LFSPXO020088Bulk on your PCB is all that you need to get a reliable oscillator. Furthermore, getting acquainted with the LFSPXO family provides a variety of oscillator designs - while the part discussed here works with a frequency of 60 MHz, additional options are available.