A linear low power remote preamplifier for the Atlas liquid argon EM calorimeter

In a previous paper, it was shown that, for shaping times of the order of the transmission line delay, a remote, external preamplifier could perform as well as one connected directly to a liquid argon calorimeter. Here we describe an improved circuit configuration where, by attributing the functions of low noise and high dynamic range to two different transistors, the linearity can be improved and the noise can be decreased while reducing the power dissipation by a factor of three (to about 50 mW). The gain (i.e., the transresistance) and the input impedance can be chosen independently without changing the power supply voltages and power dissipation