Digital log amplifier for ultrasonic testing

摘要

The apparatus and method of the present invention provides a plurality of linear amplifiers simultaneously processing an ultrasonic signal. Each amplifier of the plurality of linear amplifiers has a predetermined gain level suitable for achieving the desired output signal level for input to an analog to digital (A/D) converter for processing. The output of each amplifier is sampled by each respective A/D converter at a very high frequency to convert the analog signal output of each of the linear amplifiers to a digital signal. Logic circuits simultaneously monitor all of the output digital signals from the A/D converters. The logic circuits determine which output of the A/D converters has the greatest linear output and stores the selected output in a memory storage device. The saved output waveforms are subsequently combined into a continuous linear digital output that has a dynamic response range that is approximately the sum of the individual dynamic response ranges of the individual amplifiers and A/D converters. The combined continuous linear digital output waveform may be input to a logarithmic conversion to produce a waveform having a wide dynamic range.