Could you purpose any IC for PWM generator?

[theasus]

Could you purpose any IC for PWM generator?
Desired frequency interval is 1Hz to 300Hz.
I found some like 8038,XR2206 but they are very old IC and it is hard to assure these IC.

 

[karesz]

Hi,
What about "self made"?
With some Op Amps you have light "the solution"...
K.

 

[theasus]

ok it can be but how can i determine right circuit? Could you pupose any analog circuit for this operation?

Added after 1 minutes:

i have tried some analog circuits but i couldn't succed

 

[karesz]

Hi,
Do you need to tune it from 1Hz to 300Hz in 1 band?
K.

 

[FvM]

XR2206 is an active Exar part and available from many catalog distributors. But sine oscillator or function generator with
sine pulse shaper are of course options. A pulse shaper (as utilized in the said mononlithic function generators as well)
has the advantage of not requiring an amplitude control loop with long settling time at low frequencies. Some deviation
from ideal sine waveform must be accepted, however. Circuits have been published at edaboard before. See e.g.:

 

[karesz]

Hi FvM,
Yea, XR is a good (old) circuit, but is maked for some other_more precisouse_ jobs.
For a PWM is to good (for me), but some controlled current generator solution with for example an 555 is, I think, more as OK, or for more preciouse circuits self maked of OPs...
K.

Added after 1 hours 4 minutes:

theasus,
So, for exampl.
NS, AN-828, pp7, fig. 9 (I mean LMC555+ an OP):
www.national.com/an/AN/AN-828.pdf
LMC555 with ca. 1.5M Ohm & 1uF works at 1 Hz fein...
What do you means over that pls?

K.

 

[Tahmid]

Hi,
For operation from 1Hz to 300Hz, there are many choices. Most common would be LM555. Other choices include using NAND gates. You could also use a dedicated PWM chip like SG3526.

 

[karesz]

Hallo,
Yes, but only questions are wide-tuning band of 300 fold, AND from 1Hz...
K.

 

[FvM]

I understood, that the discussion was about a sine generator for a sine PWM (it's not exactly said in the original post,
but it would be the only understandable reason to use a XR2206). LM555 is of no particular use for this purpose.

 

[karesz]

Hi FvM,
sorry, you did misunderstand it, only you spoke over sinus, or in all cases not theasus or I...
Sincerely
K.

Added after 54 minutes:

Hi theasus,
I found yet a circuit, maybe is _after some redimensioning_ ideal/good for you?
Pulse Width Modulation:
https://www.eleinmec.com/article.asp?28
K.

 

[FvM]

I just tried to find some sense in the original post. If it doesn't mean sine PWM, it's rather absurd in my opinion.

 

[karesz]

Hi theasus,
I found the circuit what I did mean to begin; it has for example a CHEAP LM 324 (or such better/moderner version), 10-11 passives + a Potentiometer_ and as you know, LM324 is an industry type >>> you have it overall on the earth....:

I build an similar controller so ca. ten years ago, but with 4xCMOS OP from TI, it was a very good & simple solution for PWM generating + consumes ~nothing (at 1-2mA).

http://www.elecfree.com/circuit/ele...speed-controller-dc-light-dimmer-by-ic-lm324/
Original source(?): http://www.solorb.com/elect/
K.

 

[webmasterpdx]

For any kind of circuit like this, I'd stay away from discretes and just use a 50 cent PIC like a PIC12F629.

Using the timers you can have multiple PWM lines in operation. The only limitations is current draw. The chip itself only allows a max of 25mA per pin with a max of 125mA for the chip, but you can make that as high as you want by using a transistor to go to 500mA or a MOSFET to go even higher.

You shouldn't even need a crystal if you program it right to use it's built-in calibration value. Very little passives will be needed. If you have higher current needs then using the external transistors per line will add a few more components....all depends on what you want to do.

Anyways, thats my 2 cents worth.

 

[karesz]

Hi webmasterpdx,
Exactly;
As you are writing too >
"......all depends on what you want to do. "...

Hier was the question over an chip proposing for PWM generating, then maybe he dont have or even dont wish to have a PIC (or other uPs)...
Greatings!
K.