Image sensors for space applications
Caeleste has the short-term ambition to create CMOS imagers to match scientific CCDs in all respects:
- backside illumination, stitching up to wafer scale
- ILT-CCD like operation by the use of “global shutter” (GS) CMOS technology, at the same time allowing true, on-chip CDS
- low dark current by pinned diodes, and buried memory nodes for global shutter operation
where CMOS outperforms CCD
- CMOS type of interfaces, including on-chip AD conversion, extremely high data throughput, at the lowest possible power
- linear, >100dB dynamic range by Caeleste’s exclusive HDR techniques (see patents page), compatible with CDS and GS
- radiation tolerance, for TID, SEU, SET etc
Large area devices
- Stitched devices, allowing large scale devices, up to wafer scale
- Global shutter pixels, charge and voltage domain.
- Correlated double sampling
- High Dynamic range: > 100 dB
Large area devices, designed for fault tolerant operation, combine high-speed operation, low noise operation and high dynamic range to cope with unexpected illumination conditions without blooming.
Hyperspectral and TDI
- Long devices
- High frame rate
- Low etaloning
- CCD-CMOS option for TDI operation
In low orbit missions the ground resolution is almost uniquely determined by the line rate of the image sensors. Hyperspectral devices require the readout of tens, if not hundreds, of lines in a few milliseconds time frame.
In case of high-resolution imagery, TDI operation can help in increasing sensitivity beyond the capabilities of single line integration.
- Proprietary IP blocks
- Low TID effect of dark signal
- High immunity against SEL and SEU
- Reduced SEFI sensitivity
Due to special design techniques, our image sensors have low sensitivity of dark signal for Total ionizing dose. Our image sensors are immune against Single event latch-up and single event upsets. Also the effects of SE Functional interrupts can be minimized.
- Coupling with direct and indirect X-Ray absorbing materials
- Optimized Backside illumination operation for UV sensitivity
- Thick epi for increased NIR sensitivity
- Deep cryogenic operation for ROIC’s and cooled Frontend electronics
Our experience in other application fields allows us to design reliable sensors in wavelengths ranges outside the visible range. With partner foundries the image sensor processes are optimized for the UV and NIR range. We are also designing ROICs and frontend electronics for dedicated detection materials and FPA’s.