SBIR-STTR Award

Data transmission in communication systems, RADARs, satellite systems, and other military devices are dominated by analog data conversion. These high performance digital to analog converters (DAC) exceed 3Gsps with 12 bits of resolution and are readily available in the commercial marketplace, but they lack the radiation hardness required to support military satellite applications. Trusted Semiconductors Solutions has partnered with e2v, a proven commercial supplier of high performance data converters, to provide us access to DAC intellectual property. We have selected a commercial DAC that exceeds the performance requirements of this program and is well suited to hardening. The steps we will execute to harden the DAC include performing a radiation hardening assessment, retargeting the foundry technology, analyzing the radiation performance and implementing mitigation techniques. The technology we are targeting for the rad-hard DAC is a silicon germanium (SiGe) 180nm Bi-CMOS on Silicon-on-Insulator (SOI) process with 280GHz Ft’s. The resulting rad-hard DAC will have 12-bit resolution, operate at 2Gsps, SNR of >70dB and a SFDR >80dB. It will operate at TID >1Mrad(Si), SEU 1x1010 rad(Si)/s and DRS >1x1012 rad(Si)/s. This rad-hard DAC will be optimized for space based MILSATCOM and GPS applications.

Benefits:
Execution of this program provides the Air Force with a state-of-the art QML rad-hard DAC for space based MILSATCOM and GPS applications. Successful completion of Phase I and Phase II results in the delivery of a prototype radiation hardened Digital to Analog Converters. This 12-bit, radiation hardened DAC will have a sampling rate of 2Gsps, a signal to noise ratio of 70dB and spurious free dynamic range of 80DB. The DAC design and simulation work will be completed in Phase I, with the final GDSII database ready for fabrication. In Phase II, we will manufacture the DAC and test/characterize the prototype devices for performance, radiation hardness and reliability. Prototype devices will be fabricated on-shore and parts assembled in a ceramic, hermetically sealed LGA package suitable for space flight. Full-scale radiation characterization testing will be performed including total ionizing dose testing with a Cobalt-60 source, heavy-ion testing for single event effects and latch-up, proton and neutron testing. Product upgrade and MIL-PRF-38535 space-level QML qualification testing will be performed in Phase III.

Keywords:
digital to analog converter, DAC, radiation hardened, space, SOI, SiGe, QML

Data transmission in communication systems, RADARs, satellite systems, and other military devices are dominated by analog data conversion. High performance, low power digital to analog converters (DAC) that exceed 3Gsps with 12 bits of resolution and are available in the commercial marketplace, but they lack the radiation hardness required to support military satellite applications.Trusted Semiconductor Solutions designed a radiation hardened, low-power, 3Gsps 12-bit DAC in Phase I.The DAC is latch up immune, will operate at a TID > 1Mrad(Si) with SEU < 10e-10 errors/bit-day. Dose rate upset is 10e10 rad(Si)/s and dose rate survivability is 10e12 rad(Si)/s. The radiation hardened DAC implements a partially segmented architecture, which is typical for this performance class. The DAC has an SNR of 70dB, an SFDR of 76dB and operating power of 1.5W. The DAC interfaces to an ASIC or FPGA through four 12-bit LVDS ports running at 750MHz.Prototype units will be fabricated, radiation tested and characterized in Phase II. Parts will be assembled in 255-lead hermetic CCGA packages. Additionally, a DAC evaluation module will be developed and delivered for the purpose of demonstrating functionality and performance. Product upgrade and MIL-PRF-38535 space-level QML-V qualification testing will be performed in Phase III.;

Benefit:
Execution of this program provides the Air Force with a state-of-the art QML-V radiation hardened DAC for space based MILSATCOM and GPS applications. The DAC will be fabricated on-shore and parts assembled in a ceramic, hermetic LGA package suitable for space flight. Prototype units and a DAC evaluation module will be available 15 months after the start of Phase II. The DAC evaluation module can be used to demonstrate and market the DAC in parallel with the Phase III QML-V qualification efforts. In addition to Department of Defense programs, the DAC is also well suited for commercial space, avionics, industrial, medical and commercial applications.