Japanese electronics conglomerate Panasonic is presenting an innovative VLSI technology design at 2013 Symposia on VLSI Technology and Circuits to be held at the Rihga Royal Hotel Kyoto, Japan on June 11-14, where the digital signals are handled as analog signal. By using ferroelectric memristor, the continuous analog data as resistance is recorded on a CMOS (Complementary Metal-Oxide Semiconductor) circuit. Since processing analog data directly, huge power saving is achieved. These neural network type circuits have the ability to carry out processing that replicates parts of human thought, such as the ability to make judgments based on broad trends, will decrease drastically to one tenth of the energy consumption of conventional circuits, says Panasonic.
Panasonic explains "The resistance of a ferroelectric memristor can be changed continuously by an applied voltage. As the resistance is maintained without applying a voltage, it acts as a memory device. Therefore, as the device can store data as an intermediate value rather than a binary value (1/0), it is able to store more information than digital memory. Based on this large amount of information stored, through carrying out operations on the efficient analog data, it is possible to reduce the energy consumption as the amount of data to be processed increases. This development will contribute to the realization of a signal processing circuit which mimics the processing of neurons in the brain."
The developed technology has the following features as per Panasonic:
- By forming the ferroelectric memristor with a highly oriented lattice on the digital circuit, analog processing in which operations on analog data are carried out directly has been made possible. (The power consumption of the analog processing is 10% of a conventional processor when it is applied to pattern recognition.)
- In addition, since analog data stored in a ferroelectric memristor is maintained even when the power supply is cut off, the power can be cut when the ferroelectric memristor is not in use, leading to further reductions in power consumption.
This development is based on the following new technologies.
Crystal growth technique for the forming of the ferroelectric memristor on a CMOS circuit through a seed layer.
Hybrid circuit design to handle digital signals as analog data.
Panasonic says it holds 35 Japanese patents and 25 overseas patents, including pending applications, for this development.
Schematic image of a test circuit,
which has ferroelectric memristors on the CMOS circuit substrate.
(Structural cross-section (left) and scanning electron microscope image (right))
The image of the future information processing
with this developed technique.