Integrating amplifiers for PHENIX lead-glass and lead-scintillator calorimeters

Two types of integrating amplifier systems have been developed for use with lead-glass and lead-scintillator calorimeters with photomultiplier tube readout. Requirements for the amplifier system include: termination of the line from the photomultiplier; compact size and low power dissipation to allow multiple channels per chip; dual-range outputs producing 10-bit accuracy over a 14-bit dynamic range; RMS noise levels of one LSB or less; and compatibility with timing filter amplifiers, tower-sum circuits for triggering and calibration circuits to be built on the same integrated circuit (IC). Advantages and disadvantages of an active integrator system are compared and contrasted to those of a passive integrator-based system. In addition, details of the designs and results from prototype devices, including an 8-channel active integrator IC fabricated in 1.2 μm Orbit CMOS, are presented