This function generator is fully developed by myself from schematic diagram to pcb layout. The PCB is also made by myself using the UV method. The AD9834 Direct Digital Synthesis (DDS) from Analog Devices makes it easy to design a low-cost, but yet high-performance function generator. One of the benefits of using DDS for function generator is that the output signal has very low distortion and frequency can be controlled digitally. The DDS and the display are driven by PIC16F876A PIC microcontroller which software is written with mikroC.This function generator can produce output frequency from 1Hz to 10MHz which is adequate for most of the applications.The output amplitude can be controlled digitally with 1024 steps thanks to the MAX5481 digital potentiometer from Maxim.
Schematic download link:
http://rapidshare.com/files/389093146/schematic.png