A Transistor-Free Analog Content Addressable Memory with High Bit Density

In this work, we design and demonstrate a nonvolatile analog content addressable memory (ACAM) from 2-complementary ferroelectric diodes (FeD) by experimentally calibrated TCAD simulations. Apart from the unique features of FeD, including high non-linearity, multi-conductive states and non-volatility, “data line” and “coding line” configurations are implemented, where data line takes care of both search line and match line functions over the traditional CAM structure, and coding line is used to enhance the expansion of match window. The designed ACAM achieves a high bit density (up to 5 bit/cell) parallel search with minimal overlap between match windows and the smallest footprint known (<tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\sim 0.12 \mu \mathrm{m}^{2} /$</tex> cell for 45 nm node).