US Patent 7098839 Flash array digitizer

Apparatus for rapidly acquiring a large number of samples of a signal under test, stores the samples in a waveform memory without converting the samples to binary form. The signal under test is applied to an arrangement of comparators and exclusive-OR gates to provide a signal indicative of amplitude. The waveform memory is arranged in rows and columns. In one embodiment, the amplitude-indicative signal serves as a row address signal for the waveform memory, and a scanning control signal serves as a column address signal for the waveform memory. In another embodiment, an X-Y display is produced in which the column address signal is responsive to the amplitude of a second signal under test.