ANALOG-TO-DIGITAL CONVERSION USING CUSTOM CMOS ANALOG MEMORY FOR THE EOS TIME PROJECTION CHAMBER

The multiplexing scheme of custom CMOS analog memory integrated circuits, 16 channels x 256 cells, into analog to digital converters (ADC's) to handle 15,360 signal channels of a time projection chamber detector system is described. Primary requirements of this system are high density, low power and large dynamic range. The analog memory device multiplexing scheme was designed to digitize the information stored in the memory cells. The digitization time of the ADC's and the settling times for the memory unit were carefully interleaved to optimize the performance and timing during the multiplexing operation. This kept the total number of ADC's, a costly and power consuming component, to an acceptable minimum.