Charge pulse detection with minimum noise for energy-sensitive single-photon X-ray sensing

A novel charge pulse detection circuit is presented, consisting of a continuous reset resistor in series with the charge pulse generator, followed by a simple amplifier and pulse shaping circuit. Realization with a 0.18 μm CMOS process (UMC) will result in input-referred charge noise of less than 30 electrons r.m.s. at room temperature, corresponding to an energy resolution in single-photon X-ray sensing of about 110 eV.