During the study of new-generation intelligent eddy current non-destructive detector, two pieces of MAX038 are used to produce programmable wide-band orthogonal signal, which preferably solves the universal problems of generation of the signal source and the reference source in the correlative detection circuit. By use of MAX038, circuit structure of eddy current detector is simplified very much, control performance is good, and the bottleneck problem in correlation detection circuits is solved. The response of PSD to the odd harmonic frequency is eliminated, which improves the measurement accuracy. It can be expected that traditional detector will be completely replaced by intelligent eddy current non-destructive detector.