The AT68166, by Atmel, is a 16-Mbit SRAM packaged in a hermetic Multi-Chip Module (MCM) for space applications. MCM packaging technology offers the advantages of reducing PCB real estate, the number of individual components and improves overall electronic effectiveness. This allows a reduction of the PCB area by 50% with a weight savings of 75% compared to four 4-Mbit packages.
The AT68166 Multi-Chip Module incorporates four 4-Mbit AT60142 SRAM dice which are produced on Atmel’s radiation-hardened 0.25um CMOS process.
The AT68166 is a very low-power CMOS asynchronous SRAM. It can be organized as either one bank of 512K x 32, two banks of 512K x 16 or four banks of 512K x 8. It combines rad-hard capabilities – a latch-up threshold of 80 MeV.cm squared/mg and a total dose of 300-Krad – with a fast access time. The AT68166 operates at 3.3V and is available in two versions: the AT68166FT with 5V-tolerance inputs and the AT68166F for 3V operation. The access times are respectively 25 ns and 20 ns over the full military temperature range. The AT68166 MCM offers low power consumption: 540 mW per byte at 25 ns and 620 mW per byte at 20 ns.
The AT68166F/FT are available in a 68-lead flat pack; they weigh 8.6 grams thus meeting the rigorous size and weight requirements of the space industry. Also, thanks to the small size of the 4-Mbit SRAM, Atmel has been able to accommodate the assembly of the four dice on one side of the package which facilitates the power dissipation.
The AT68166 is a cost-attractive alternative to existing 16-Mbit SRAM offerings. The compatibility with other products allows designers of space applications to easily migrate their designs to the Atmel AT68166 memories.
Pricing and Availability
Samples and production parts are available for both variants. The AT68166 is QML Q and V qualified and supported by the SMD 5962-06229. The AT68166 is priced at $1,710 each, in QML Q, for 100 pieces. In early 2007, the access times will be improved from 20-25 ns to 18-20 ns.