![]() By varying the relative amplitude of the signal sent to each speaker, an artificial direction (relative to the listener) can be suggested. Secondly artificial or pan stereo, in which a single-channel ( mono) sound is reproduced over multiple loudspeakers. The signal is then reproduced over multiple loudspeakers to recreate, as closely as possible, the live sound. ![]() ![]() Stereo sound systems can be divided into two forms: the first is true or natural stereo in which a live sound is captured, with any natural reverberation present, by an array of microphones. Two microphones set up to record a piano simultaneously, which creates a stereo sound The word stereophonic derives from the Greek στερεός ( stereós, "firm, solid") + φωνή ( phōnḗ, "sound, tone, voice") and it was coined in 1927 by Western Electric, by analogy with the word stereoscopic. Stereo sound has been in common use since the 1970s in entertainment media such as broadcast radio, recorded music, television, video cameras, cinema, computer audio, and internet. Binaural sound systems are also stereophonic. ![]() This is usually achieved by using two independent audio channels through a configuration of two loudspeakers (or stereo headphones) in such a way as to create the impression of sound heard from various directions, as in natural hearing.īecause the multi-dimensional perspective is the crucial aspect, the term stereophonic also applies to systems with more than two channels or speakers such as quadraphonic and surround sound. Stereophonic sound, or more commonly stereo, is a method of sound reproduction that recreates a multi-directional, 3-dimensional audible perspective. This device operates very similarly to the flash cell above.Time difference in a stereophonic recording of a car going past THere is another class of device that is called a MNOS transistor (Metal Nitride Oxide Semiconductor) in which tehere are two dielectrics in the gate, one of which is Si3N4 which has a lot of traps. Smith, PD, M Kucic, and P Hasler, “Accurate programming of analog floating-gate arrays,” IEEE International Symposium on Circuits and Systems, Volume 5, May 2002, pg V-489. Lee, BW, BJ Sheu, and H Yang, “Analog floating-gate synapses for general-purpose VLSI neural computation,” IEEE Transactions on Circuits and Systems, Volume 38, Issue 6, June 1991, pg 654.įujita, O, and Y Amemiya, “A floating-gate analog memory device for neural networks,” IEEE Transactions on Electron Devices, Volume 40, Issue 11, November 1993, pg 2029. Here are 3 references from an EDN article talking about a company called GTronix which was acquired by National Semi (now TI). Just to be clear here, I am talking about the individual device/transistor not the complete component as the support circuits of a Flash will prevent you from operating the cells in this way. It will be stable over weeks to months so it meets the requirements of hours that you say you'd need.īut a lot depends upon the specifications that you need, how much drift is acceptable etc. While non-linear it is a proportional effect so you could imagine designing a circuit that linearized the programming effect (of Vth shift). The programming charge can be variable though somewhat unpredictable as the FN tunnelling (Fowler Nordheim) will be variable across the die. It is a Floating Gate MOSFET, used in Flash memory, EEPRom and the ilk. This device does exist although it's not readily available in single unit quantities, its output amplifiers will get in the way and it's very non-linear. ![]() However, other technologies can enable the vision when combined with a software software reconfigurable mux. Given the inability to scale, the longer term vision is probably not practical. My longer term thinking was this technology could be developed further for use in AI and used in conjunction with n fan-out non-blocking, reconfigurable non-volatile multiplexers.įast forward about 15 years - Xicor ended up developing such a device and then subsequently was acquired by Intersil. Since I was also associated with LTC, which was one of the leaders in precision voltage references that were inherently power hungry, that led me to think a single EEPROM cell could be adapted to be a high precision and very low power voltage reference. Given the thick oxide didn't "leak" electrons, I asked the designers at Xicor about the theoretical resolution of a single thick oxide cell if we discounted the limitations of the sense amps, and they said it could approach 1ppm (roughly 20 bits). There were other issues, but they don't apply here. Thin oxide leaked charge and thick oxide was inherently impossible to scale. In the early days, there were weaknesses to both routes. EEPROM technology split into two branches in the early 1980s - one thin oxide (FLOTOX) with Intel and Seeq and the other thick oxide (Xicor). ![]()
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