Method and apparatus for combinatorial logic signal processor in a digitally based high speed x-ray spectrometer

A digital combinatorial logic circuit for analyzing a digital representation of an electronic signal containing step-like pulses, which arrive at an average input rate R, to provide estimates of the amplitudes of at least some of said step-like pulses, said representation having been created by digitizing the electronic signal with an analog-to-digital converter (ADC) operating at a sampling frequency S which is greater than R, the representation being referred to as the digitized input signal, the circuit being clocked at frequency S or a multiple thereof, the circuit comprising:

• a digital shaping filter receiving the digitized input signal and providing an output signal referred to as the filtered signal;
• a pulse detector receiving the digitized input signal and providing an output signal representing the detection of a pulse in the digitized input signal;
• an output buffer coupled to said digital shaping filter and operable to capture a value of said filtered signal in response to a trigger signal;
• and
• a timing circuit coupled to said pulse detector and to said output buffer, said timing circuit providing a trigger signal in response to the detection of a pulse, said trigger signal being delayed relative to said output signal from said pulse detector by an amount that depends on at least one characteristic of said digital shaping filter.