| Summary: | 碩士 === 國立臺灣科技大學 === 電機工程系 === 103 === Analog memory programming systems and circuits are proposed and researched in this thesis. The analog memory information is in the form of non-volatile charge stored at floating-gates, which are surrounded by high-quality insulators. The memory can be programmed precisely by using Fowler-Nordheim tunneling and hot carrier injection mechanisms. Therefore, the analog memory programming systems are composed of floating-gate transistors, voltage generation circuits, current sensing circuits, and computation units. A programming system was first realized by using off-the-shelf digital-to-analog converter chips, bulky current sensing equipment, FPGA, and personal computer. The required time is more than 30 seconds to program one analog memory unit using such a system. To shorten the programming time and reduce the cost of required equipment, an on-board logarithmic amplifier chip and analog-to-digital converter chips are employed to replace the expensive current sensing equipment. To save the command transmission time, the computation units are moved from personal computer to the microprocessor synthesized in FPGA. The programming time can be reduced within 3 seconds for one analog memory unit.
To further improve the programming speed, some voltage generation circuits are designed and integrated into the chip with analog memories. The circuit for the analog memory unit is modified to enable larger programming range as well as to shorten programming time. Besides, each analog memory unit can be individually selected and programmed in an array without affecting others. An integrated logarithmic amplifier is designed and characterized to reduce the number of off-chip components. In this platform, the programming time for each analog memory unit can be reduced to 300 msec. The same programming infrastructure is also applied to serial-to-parallel interface circuits with non-volatile memories.
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