Rad-Hard CMOS Crystal Oscillator

摘要

There is a need for rad-hard crystal stabilized clock sources with at least 300 krad of total ionizing dose (TID) immunity. A common solution has been to spot-shield a commercial off-the-shelf part or enclose it in a vault. Rad-hard clock sources are needed for main electronics boards (MEBs) and readout electronics that need to operate in hazardous space environments. Remote sensing and telemetry require that the readout circuits be co-located with the sensors, which can be separated by an arbitrary distance from the data processing electronics.A locally generated clock signal allows the readout to generate its own clock signals and to transmit the resulting data to a remote receiver. If a crystal stabilized carrier signal was available, the readout could derive a clock signal that is an integral submultiple of that carrier and use the data generated from the clock signal to modulate the carrier. The radiation hardened by design (RHBD) CMOS crystal oscillator may be used directly or scaled in frequency to clock an application circuit.