SFG-1000 Series, an economic function generator with high accuracy and high stability output, is designed based on the DDS (Direct Digital Synthesis) technology embedded in a large scale FPGA. The frequency range of 3MHz and the output waveform selection as Sine, Square, Triangle and TTL of SFG-1000 Series adequately provide the fundamental features to ensure high confidence for the test results. The DDS technology at an affordable price gives a high-value solution to the users who need a signal source for accurate but unsophisticated measurement applications.