Direct Digital Synthesizer Evaluation Board

The ISL5314EVAL2 provides a means for evaluating the ISL5314, 125MSPS, direct digital synthesizer (DDS). The board is controlled with software that allows for any clock frequency and output frequency within the abilities of the ISL5314 to be evaluated. The interface between the PC and the evaluation board is via the parallel port of an IBM-compatible PC. The analog output of the DDS can be analyzed on external measuring equipment; typically either a spectrum analyzer or an oscilloscope. The clock source for the DDS can either be a user-changeable crystal or an external signal generator provided through an SMA connector.

The board is shipped with a 125MSPS crystal. The complementary analog outputs of the DDS are processed through a 1:1 transformer. The board can be reconfigured to bypass the transformer and only a single-ended output used. Because there is an on-chip comparator, the means to process the analog sine wave from the DDS output into the comparator inputs is provided for square wave generation. The comparator's output is provided via an SMA connector.