Input and output stations for multilevel storage CCDs

Problems of multilevel storage in CCDs are the need for high-standard technology as well as for simple and reliable input and output circuitry. This paper reports on novel input and output circuits and on first test results. Some major features of the proposed scheme are: No linear amplifiers, only one reference voltage, no extra clocks, number of charge levels selectable according to technology performance. First test devices showed reliable 3-bit-operation and, in analog mode, detection of 15 out of 16 planned levels.