The XR2206 is not a common component today, but if you have one you can build this function generator. Square, triangle and sine signals can be produced in frequency is up to 100 kHz. The circuit is poewred from a 12 V suply. Capacitors ranging from 1 nF to 1 µF allow the circuit to operate in frequencies between 10 Hz and 100 kHz. A 2M2 potentiometer adjusts the frequency along each range.
Function Generator Using the XR2206