Newsletter – September 2019 – 2
EV12DS480, the 12-bit 8 GSps DAC designed for Newspace systems
Aiming at being integrated in high-reliability high-performance space applications, the EV12DS480 DAC has been tested to assess its performance behavior in harsh space environment. The EV12DS480 is a 12-bit 8 GSps DAC, ready for space applications, designed for Newspace systems, offered in various reliability grades (including NASA Grade 1). The hardness assurance tests include Heavy Ions (HI) and Total Ionizing Dose (TID) measurements. TID tests are performed to evaluate the functionality and performance parameter drifts of the Device Under Test (DUT). During the HI tests, the Single Event Latch-up (SEL) and Single Event Effects (SEU, SEFI, SET) have been evaluated.
Complete radiation test reports are available to download on the EV12DS480 product webpage.
Total Ionizing Dose test results
Several devices are curently under test with a dose rate of 10 mrad/s. At 100 krad(Si), all the DUTs are fully functional.
The EV12DS480 has neither functional failure nor parameter drift up to 100 krad(Si) with a dose rate of 36 rad/h (10 mrad/s).
The targeted cumulative dose is fixed at 150 krad(Si) and the test conclusion will be provided as soon as the dose is reached.
Heavy Ions test results
HI tests were performed at various sampling rates (4.5 GSps, 6 GSps and 8 GSps), at the RADEF facility, part of the Accelerator Lab in the Department of Physics at the University of Jyväskylä, Finland.
Here are the conclusions of the tests:
- No SEL was detected during the irradiation with a LET of 60 MeV.cm²/mg, with no tilt. 3 DUTs were tested at Tj=135°C, with maximum power supplies + 10%.
- SETs were observed during the irradiation from 3.6 MeV.cm²/mg to 69.3 MeV.cm²/mg, at room temperature and typical power supplies.
- SEFI were observed during the irradiation from 3.6 MeV.cm²/mg to 69.3 MeV.cm²/mg but all these SEFI were successfully managed by software reconfiguration of the DAC registers (no RESET, no power-up cycle required).
- There is no significant gap between SET/SEFI cross sections obtained in the different modes.
- There is no significant gap between SET/SEFI cross sections obtained for DACOUT and DSPCLK output signals.
- There is no impact of the sampling rate of the device, the SEFI cross section remains the same whatever the clock frequency is (4.5 GHz, 6 GHz or 8 GHz).
These SEE results show that the EV12DS480 DAC, can be used as a space product.
DUT in the heavy ion irradiation chamber:
As an illustration of these results, the SEE rate is calculated based on the OMERE code, and DACOUT signal output measurements, for GEO missions:
|Weibull fit Parameters||SEE Rate Calculation|
|s||Threshold (critical) value of LET
|Saturation Cross-Section (cm²)||Mission (GEO)||Rate/Day||MTBF (Days)|
 SEU: Single Event Upset
 SEFI: Single Event Functional Interrupts
 SET: Single Event Transient
 MTBF: Mean Time Before Failure
 M3: Cosmic rays solar min
 M8: Solar eruption, worst-case flux