关键词: 阻抗匹配；数控阻抗；FPGA

Abstract: An automatic impendence matched circuit digitally controlled impedance（DCI）is designed which meets the requirements of signal integrity when using ultra-large-scale field programmable gate array (FPGA) in industrial control and aerospace. DCI adjusts the output impedance or input termination to accurately match the characteristic impedance of the transmission line. DCI actively adjusts the impedance of the I/O to equal an external reference resistance. This compensates for changes in I/O impedance due to process variation. It also continuously adjusts the impedance of the I/O to compensate for variations of temperature and supply voltage fluctuations.

Key words: impendence match; digital controlled impendence; FPGA