Thermoelectric Cooling to Survive Commodity DRAMs in Harsh Environment Automotive Electronics

Today, more and more commodity hardware devices are used in safety-critical applications, such as advanced driver assistance systems in automotive. These applications demand very high reliability of electronic components even in adverse environmental conditions, such as high temperatures. Ensuring the reliability of microelectronic components is a major challenge at these high temperatures. The computing systems of these applications rely on DRAMs as working memory, which are built upon bit cells that store charges in capacitors. These commodity DRAMs are optimized for cost per bit and not for high reliability. Thus, very high temperatures impose an enormous challenge for commodity DRAMs as the data retention time and reliability decrease largely, affecting the data correctness. Data correctness can be ensured up to certain temperatures by increasing the refresh rate to counterbalance the retention time reduction. However, this severely degrades the access latencies and the usable DRAM bandwidth. To overcome these limitations, we present for the first time a Thermoelectric Cooling (TEC) solution for commodity DRAMs in harsh-environments, such as automotive. ... mehrOur TEC solution enables the use of commodity off-the-shelf DRAMs in safety-critical applications by reducing the temperature conditions to a range where they can operate reliably. This TEC solution is applied a posteriori to the DRAM chips without using high-cost package solutions. Thus, it maintains the low-cost targets of such devices, improves the reliability, and at the same time, counterbalances the adverse effects of increasing the refresh rate. To quantitatively evaluate the benefits of TEC on commodity DRAMs in harsh-environments, we performed system-level evaluations with several applications backed up by the measured data on commodity DRAMs. Our experimental results, using accurate multi-physics simulations that employ finite element method, demonstrate that the TEC-based cooling ensures that the maxim...