Active control of the baseline of digitized preamplifiers with sliding-scale correction

We present a negative-feedback control structure which forces the analog voltage of digitized preamplifiers to stay within the ADC input range, even when the preamplifier fall time is long (ms range) and the event rate is high (100 kHz range). A suitable voltage is dynamically added to the preamplifier signal so as to cancel the baseline shifts brought about by event pileup, low-frequency disturbances, hum and microphonisms, so preventing saturation of the ADC. The preamplifier signal is then fully reconstructed using a sliding-scale scheme, over a dynamic range well larger than that of the ADC.