Temperature measurement in Content Addressable Memory cells using bias-controlled VCO

With increasing speed and power density, high performance memories have now begun to require dynamic thermal management (DTM) as processors and hard-drives did. Memory thermal limits (threshold values for throttling) are set-based on worst-case power data which leads to over-guard-banding and performance degradation. To ensure an accurate and closed-loop throttling mechanism we need physical thermal sensors in the memory module. We propose a low power/area temperature extraction scheme for content addressable memory (CAM) cells at a resolution of 5degC. We modify the CAM circuit to amplify the static currents in inactive mode and map the temperature-dependent leakage current to a frequency value using a bias-controlled VCO.