DRAMS with ECC offer soft-error-robustness at 125°C operating temp

August 21, 2015 // By Graham Prophet
Intelligent Memory (IM), a fabless memory manufacturer, has a family of very robust DRAM components withstanding even the highest operating temperatures and stress, available from distributor Memphis Electronic AG (Bad Homburg, Germany). IM claims an industry first with 125°C operating temperature DRAMs.

In automotive, avionic, aerospace and military applications, notes IM, components are often under extreme stress in high temperatures and/or radiation. High temperatures cause the leakage of the capacitors in DRAMs to increase rapidly, leading to transient single bit errors, also called soft-errors. In addition, the DRAM cells tend to degradate quickly under stress, which further reduces the data-retention time of the cells, making it difficult to guarantee a soft-error-free long-term operation.

Most manufacturers of automotive DRAM require a doubled or quadrupled refresh-rate to work against these physical limitations of DRAM cells. Besides the fact that higher refresh-rates consume more power and generate more heat-dissipation, this method still entails a high risk due to the unknown degradation that may lead to random soft-errors only after weeks or months of use of the DRAM product.

Based on its ECC DRAM technology, Intelligent Memory offers DRAMs that can operate stably even at 125°C without the requirement to increase the refresh-rate. With their integrated Error Correction Code, IM ECC DRAMs correct single-bit-errors caused by any kind of root-cause, such as heat, radiation or degradation. Most bit-pattern-dependent bit-flips and even permanent single-bit hard-errors can be caught by the on-chip ECC logic.

Joseph Chan, General Manager of Intelligent Memory, explained "IM is aiming to set new a standard for DRAM reliability for the safety-critical industry. Our eXtra Robustness ECC DRAMs (XR DRAM) have already proven their radiation-hardness. Now we want to show the automotive and avionic market that IM has the perfect solution for the increased demands of high operating temperature and reliability without any performance-loss. Our products are made for the markets that require long-term availability without revision shrinks."

The new products with a temperature range of -40 to 125°C named "Extreme Temperature" or "X-Grade" ECC DRAM are sampling now in DDR3 technology having a capacity of 1 Gigabit (part# IM1G16D3EEBG-15EX), with DDR2 and DDR1 products to follow later. AEC-Q100 Automotive Grade 1 qualified DDR3 parts are planned to be sampling by November 2015.