IN Brief:
- LX-820 adds a quartz timing option for low-Earth-orbit electronic systems.
- Space component selection depends on radiation and thermal performance.
- Distinguish its oscillator function from Microchip’s separate PIC64 computing programme.
Microchip has introduced the LX-820 radiation-tolerant quartz oscillator for low-Earth-orbit spacecraft in a 3.2 by 2.5mm surface-mount package. The component is specified for -55°C to +125°C operation and ±100ppm performance. CMOS-output versions span 1.25MHz to 135MHz, while LVDS-output versions cover 100MHz to 250MHz.
Microchip positions the device within its L-Series timing range, between general commercial-off-the-shelf oscillators and more extensively screened traditional space-grade products. The design is intended for spacecraft clocks whose electrical performance, environmental tolerance, supply schedule and package size must be balanced against individual mission requirements.
Timing errors can affect several subsystems at once. A communications transceiver uses a reference clock to determine carrier frequency and data conversion timing; a microprocessor relies on clocks to sequence operations; and data acquisition may need consistent sampling intervals to interpret sensor outputs. A small error can accumulate or influence frequency accuracy, depending on how the reference is distributed. The specification of a clock source therefore requires attention to stability, phase noise, ageing and the quality of downstream buffers and power supplies.
Quartz devices can offer accurate and compact timing, but their frequency changes with temperature and can drift over life. Spacecraft electronics face repeated thermal cycles as an orbit moves between sunlight and shadow, while vibration during launch adds a different environmental stress. Designers must consider the oscillator’s actual mounting, thermal environment and interactions with the local power rail. Qualification should assess the complete component under representative electrical conditions, rather than extrapolating from a nominal room-temperature frequency tolerance.
Radiation exposure matters because energetic particles can upset or degrade semiconductor control circuitry associated with a timing component. The orbital environment varies with altitude, inclination, mission duration and shielding. A product developed for LEO may not be suitable for a deeper-space mission with a very different radiation profile.
Engineers need to compare stated total-dose, single-event and other applicable test results with their spacecraft’s mission analysis. The label radiation-tolerant should not be treated as a universal classification covering every environment.
Component procurement in space programmes also places weight on lot control and documentation. A timing part selected for an initial payload may require ongoing availability through several design revisions and test campaigns. Manufacturers generally assess solderability, mechanical constraints, vibration performance and relevant screening steps before approving a device for a flight build. The fact that a device appears in a space-focused product family does not eliminate application-specific acceptance testing or documentation.
The oscillator must also be considered within a clock tree. Driving several loads through traces with different lengths and impedances can introduce skew, ringing and sensitivity to noise. Boards using sensitive receivers or precision converters may require careful clock routing and local regulation. If a spacecraft uses redundant electronics, the timing architecture may need a controlled method for selecting between references and recovering from failure without disrupting essential functions.
The interface specification also matters because a clock signal is not useful in isolation. Oscillator output format, supply voltage, frequency range, start-up time and load drive must be matched to the equipment receiving the reference. A timing device that starts slowly may affect a spacecraft controller’s boot sequence, while an unexpected output state can complicate fault recovery.
Designers should evaluate conditions after brownouts and partial power failures, not solely steady operation. Detailed data-sheet limits and component screening are necessary before choosing a final flight configuration. Operating data should include conditions at beginning and end of life, with enough margin for the complete clock distribution circuit rather than simply the oscillator’s nominal output.
The LX-820 gives spacecraft designers another timing option that balances a compact 3.2 by 2.5mm footprint, wide temperature operation and frequency ranges matched to CMOS or LVDS interfaces. Microchip describes the device as engineered towards MIL-PRF-55310 Level B requirements; this should not be confused with a statement that every production lot has completed a particular customer’s mission qualification. Its suitability depends on radiation-screening evidence, actual stability requirements and the rest of the clock distribution architecture. Engineers must qualify the part against launch and orbital conditions rather than assuming that its radiation-tolerant description extends to every possible space environment.
