Total dose radiation exposure results in charged defect densities in the gate and isolation oxide regions of a MOS transistor. The charged defects degrade device performance by introducing changes in threshold voltage and leakage current. The magnitude of the parametric shift is dependent on operating conditions and environment.
The Ridgetop RadCell VT prognostic cell accurately senses radiation-induced shift in CMOS transistor threshold voltage and outputs the cumulative degradation result. It is a part of the Sentinel Silicon™ library of prognostic (“canary”) cells
The prognostic distance is the time between the prognostic cell warning point and the time of system failure, as shown below. The prognostic distance of the RadCell Vt prognostic cell can be adjusted to meet customer needs by trigger point calibration.
Determining the Prognostic Distance
Features and Benefits
- Acts as an early-warning sentinel of an upcoming threshold voltage failure condition due to radiation exposure
- Available for various CMOS processes
- Power dissipation is approximately 600 μW
- Prognostic distance can be adjusted from the nominal 80% point
- Simple buffered logic high or low output indicate an impending failure event
- Optional IEEE-1149.1 JTAG Bus interface
For more information, please contact us or follow the links below.
Ridgetop is certified as category 1A under the Defense Microelectronics Activity (DMEA) as part of the Trusted Supplier Program. Ridgetop has history of designing analog and mixed signal ICs for demanding applications in space satellites that are subjected to extreme temperatures and radiation. Our designs have utilized bulk CMOS, CMOS-SOI, and SiGe at process geometries down to 28 nm channel lengths. Radiation hardness is also a concern, and Ridgetop has addressed those requirements as well. A recent Ridgetop design was delivered to ON Semiconductor for the U.S. Air Force STELLAR Star Tracker.
Under contract to NASA, Ridgetop designed an effective 3-axis wireless rotational sensor. The RotoSense™ sensor has been tested on fast-spinning pinion gears on helicopter gear boxes, and also rolling stock for railroad safety improvements.