Phase-Plane Approach to the Compensation of High-Speed Analog-to-Digital Converters

摘要

This paper outlines a practical method for decreasing the harmonic distortion of high-speed (1 to d100 MHz) analog-to-digital converters (ADC's), making them more suitable for Fast Fourier Transform (FFT) spectral analysis applications requiring wide dynamic range. The basis of this method lies in the application of a two-dimensional correction table to the converter's output sequence. A correction value for each ADC output state is accessed by both the output state itself and an estimate of the slope of the analog input at the time of conversion, hence the name 'phase-plane compensation'. Two example applications of this technique upon real converters show reductions of up to 30 dB in dominant distortion components. These improvements were obtained without the use of a sample-hold component in front of the ADC.