Yong-sik Seok

Temperature-compensation circuit techniques for high-density CMOS DRAMs

Temperature-compensation circuit techniques are presented for the CMOS DRAM internal voltage converter, the RC-delay circuit, and the back-bias generator, which do not need any additional process steps. The above-mentioned circuits have been designed and evaluated through a 16-Mb CMOS DRAM process. These circuits have shown an internal voltage converter (IVC) with an internal voltage temperature coefficient of 185 ppm/ degrees C, and an RC-delay circuit with a delay time temperature coefficient of 0.03%/ degrees C. As a result, a 6.5-ns faster RAS access time and improved latchup immunity have been achieved, compared with conventional circuit techniques. >

A 35 ns 64 Mb DRAM using on-chip boosted power supply

An on-chip boosted power supply is necessary for ease of layout and high speed in high density DRAMs. The technique of TTL conversion is a key to designing high speed DRAMs for 3-V operation. The authors present the generation and regulation of an on-chip power supply (V/sub pp/) within 50 mV of the optimum level during operation for a given V/sub cc/. In addition to the regulated V/sub cc/ scheme, improved interface circuit techniques are employed to achieve fast input and output conversion with good noise margins. An experimental 64-Mb DRAM is designed. A typical access time of 35 ns is obtained by measurement.<<ETX>>