Monolithic electronics for the WA98 leadglass calorimeter

A set of electronics have been constructed, installed and operated for the 10,800 element leadglass photon calorimeter that is part of CERN experiment WA98 studying photon production in relativistic heavy-ion collisions of 160.A GeV208Pb with targets of Ni, Nb and Pb. Two custom monolithic CMOS circuits were developed for this project. One chip includes 8 channels each of integrator, dual gain amplifier, fast amplifier, and CFD, as well as calibration circuits for amplitude and timing, threshold DACs, and current-mode trigger sum and discriminator. The second includes 16 channels of analog memory, 8 channels of TAC, a 24-channel Wilkinson 10 bit ADC, and buffers. The system is implemented as 72 144-channel circuit boards. Custom interface boards were also developed. A set of 26 model TMS320C40 digital signal processors is used to collect, zero-suppress and format the output data. Experience with data-taking using the 208Pb beam will be reported