I have designed and built two function generatos one based on the integrated circuit ICL8038 and the other based around a cmos chip and colpitts oscillator. The first one allows the size to remain very small while the second one does require some extra space for the placement of compnents.

The Integrated Function Generator (ICL8038)

The Discrete Function Generator

To help with understanding I will from here on out divide the information evenly between the IC version and my discrete circuit. But before I create a thesis and antithesis let me first give the median which joins them in functionality.

Just some ideas I'm using while putting this thing together on breadboard.

Prototyping the Frequency generating section:
Chips:
cd4047 -square wave gen.
TL082 -op-amp
mc14093 -schmidt trigger
icl8038 -function generator LF (sine and triangle + low frequency square wave)
The problem at had is the lack of high frequency sine and triangle outputs (practical limitation is to something less than 1mhz which is not very good for a function generator) other problems include the lack of of a reliable sine wave output the current one may have spikes of intolerable acceptance If it would be possible to connect the cd4047 to turn it into a sine and triangle generator the reliability and frequency control could be increased also if the factors are made to simply depend on the generation of a square wave duty cycle can easily be varied even using a different square wave generator such as the 7555 timer which runs high frequency and extremely low voltage spikes. research:
A great site: http://www.interq.or.jp/japan/se-inoue/e_ckt18.htm
wanted results from the function generator:
-square wave output
-sine wave output
-triangle wave output

-sawtooth output
(all outputs capable of at least one megahertz without distortion)
All outputs require frequency control
--want pulse width and period control
-amplitude control (can be achieved easily enough by amplifier)

Last updated: 03-30-03

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