Microchip Technology said on the 14th that it has released the ultra-compact atomic clock "Space CSAC-SA65," which can be used on small satellites and low Earth orbit (LEO) satellites. An atomic clock measures time based on the constant vibration of atoms, setting time more precisely than general electronic clocks.
The product targets the "New Space" market, where private corporations lead space development and commercial services. The company said demand is rising for space-grade electronic components that are small and consume little power as satellite communications using small satellites, positioning and navigation services, and Earth observation increase.
Space CSAC-SA65 was developed based on Microchip's existing chip-scale atomic clock, "Space CSAC-SA45." A chip-scale atomic clock (CSAC) is a product that implements the function of an atomic clock at the scale of a semiconductor chip. It is easier to mount on satellites than a large atomic clock.
The product is designed to withstand radiation that occurs in space. Its radiation tolerance is at least 30 kilorads (kRad). kRad is a unit that indicates the amount of radiation a semiconductor can withstand. The operating temperature range is from minus 40 degrees to 80 degrees Celsius.
Power consumption is under 120 milliwatts (mW) and volume is under 17 cubic centimeters (cc). For satellites, reducing component size, weight, and power consumption is important due to launch expense and payload space. In particular, in low Earth orbit satellite projects that launch multiple small satellites, these conditions directly affect product design.
Another feature is that it can maintain accurate time for a certain period even without continuously receiving time information from outside. Satellites generally set time using external signals such as the Global Navigation Satellite System (GNSS). GNSS refers to a navigation system that provides position and time using satellites, like the U.S. GPS.
Space CSAC-SA65 is designed to use the clock's inherent high time stability to set the time of onboard satellite equipment even when it is difficult to continuously receive external signals. It also has 1PPS (pulse per second) input and output functions that allow various satellite equipment to operate based on the same time. 1PPS is a method of synchronizing time between equipment by sending an electrical signal once every second.
Microchip said the product can be used for time and frequency control of LEO satellites, onboard reference clocks, and maintaining positioning, navigation, and timing information. It can also be used for "cross-link" communications between satellites.
In particular, it can be applied to an "assured positioning, navigation and timing (A-PNT)" system that maintains positioning, navigation, and timing information even when external navigation signals are cut off or jammed. On satellites and aircraft, accurate time information is used as the basis for position calculation and synchronization of communications equipment.
Space CSAC-SA65 is produced using a commercial off-the-shelf (COTS) approach that leverages commercial electronic components with radiation tolerance. COTS refers to products made using already commercialized parts and technologies, rather than components developed separately from scratch for a specific space mission.
Microchip said this can shorten the time required to supply products compared with traditional space and aviation components and also lower expense. Space-grade electronic components require high reliability and radiation tolerance, so development and verification take more time than for general commercial parts.
Randy Brudzinski, vice president of Microchip's frequency and timing systems unit, said, "As one of the lowest-power atomic clocks can now operate reliably even in extreme environments, even the smallest CubeSat can be operated with atomic clock-level accuracy," and added, "It supports maintaining synchronization and time accuracy even in environments where external time reference signals are not available."