I am in the process of building several test equipment devices as it is a lot more convenient to work on projects at home, as opposed to running to the lab every time I need something: psu, function gen, etc...
I am on the function generator and have downgraded to a square pulse generator as I have yet to find any of the available chips I have researched that I thought would be great: MAX038 - discontinued, xr2206 - rare (well, I found it but they are in Australia), and the irl8308 (NTE864) but the chip is $50.00.
Also, the square wave pulse is absolutely crucial for uC's, and I really don't
need the other wave forms.
My minimum requirements for the square pulse generator are:
1. Adj. Frequency: 1Hz to 10Khz (1Mhz would be great though)*
2. Adj. Duty Cycle *
3. Adj. Amplitude
(*with the Freq. and Duty independent, and also where the problem lies with simple 555's, I think
)
SO I was wondering, is it possible to adj. both the frequency and duty on a 555 timer? If so, will one affect the other? It was my understanding that when using a simple 555 for this idea, if I adj. the frequency, it would affect the duty?
Do you think I can accomplish my goal with this circuit?
square wave gen
Otherwise I guess I will just figure out how to make an adjustable square wave pulse generator using an MSP4302012.
Any ideas? Any other function generator chips like the MAX038, or especially the XR2206, that you know of would be great.