New Developments in Time and Pulse Height Digitizers

Recent progress in LSI circuits has brought monolithic flash ADCs and RAMs, capable of operating up to 100 MHz. They open new possibilities to designers of time and charge digitizers. A simple technique to increase the dynamic range of a 6 bit/30 MHz low cost ADC has been developed. The transfer function is approximately logarithmic and covers a 9 bit dynamic range. An application of the same ADC to measure directly the charge division in a sense wire of a wire chamber is discussed. A fast 256 × 4 ECL RAM has been tested as a buffer memory of the ADC but also as the main element in time digitizers.