Using an LM331 in your projects.
LoopyByteloose
Posts: 12,537
The LM331 is an interesting little 8 pin DIP. It converts a voltage to pulses from 10hz to 10K hz, and operates at 5 volts or more.
I accidentally bought a half-dozen some years ago when I really wanted some op-amps.
It might make a handy low voltage indicator on a Propeller device. Or it might allow you to adjust the current applied to charging a battery according to the voltage level.
And, it can drive a power transistor attached to a 5 watt speaker for an audio noise maker.
It can even be a sophisticated and accurate (down to .01%) way to measure a voltage.
Has anybody ever tried to use one? http://www.ti.com/lit/ds/symlink/lm231.pdf
I accidentally bought a half-dozen some years ago when I really wanted some op-amps.
It might make a handy low voltage indicator on a Propeller device. Or it might allow you to adjust the current applied to charging a battery according to the voltage level.
And, it can drive a power transistor attached to a 5 watt speaker for an audio noise maker.
It can even be a sophisticated and accurate (down to .01%) way to measure a voltage.
Has anybody ever tried to use one? http://www.ti.com/lit/ds/symlink/lm231.pdf
Comments
Primarily used as an Analog to Digital converter.
Also can be used as a Digital to Analog converter, among other things.
I have found it easy to use.
This VtoF is quite stable and has little sensitivity to supply variations and noise because the circuit is based on a comparator and current sources. In some applications it is much more stable than the LM555.
Even so good supply bypass caps should still be used.
On the downside it does consume 4mA or so.
And in the big picture of things they are kind of expensive.
What application do you have in mind.
Duane J
The spectrometers I service use V to F converters to analyze the composition of materials. They have an advantage over ADC chips for this application because of the wide dynamic range they can cover. An OES metal analyzer can measure some elements down to the ppm range, and an ICP can get down to the parts per billion range using V to F converters and 32 bit counters.
Must try not to buy, but $3.39 free ship Ebay... http://www.ebay.com/itm/1-pcs-LM331-Voltage-to-Frequency-Converter-DIP-New-/260844288272
Someday, I may have a brainwave and find a use for them.
An IR thermin is beginning to seem attractive.
I have used these in the past in synthesizers:
http://www.ebay.com/itm/10pc-ICL8038CCPD-ICL8038-DIP-14PIN-IC-ICs-NEW-BX27-/250930207539?pt=LH_DefaultDomain_0&hash=item3a6c9b1b33
'
as the have Sine, Square, and Triangle wave output.
Seems all come from China right now. Hmm..can they be trusted?
I have 8 genuine Intersil 8038's from 1976-1977 that I am going to put through the paces with a Propellor setup.
I'll see if the Chinese parts are up to par.
http://www.intersil.com/en/products/other-analog/special-analog/other-miscellaneous/ICL8038.html#0.html
LM331N
The shipping isn't free of course, but you should be able to add a couple to an order without increasing the shipping cost.
At least until they stopped making them a few years ago.
I was really bummed. I still have a couple but can't use them for new designs.
The Chinese sound like they started up a line for these.
I hope so, as these were very useful at making sinewaves and triangle waves.
Hope their good.
Duane J
I'll report back in a new thread when I receive them.
A trusted distributor at $25.90:
http://www.futurlec.com/Harris/ICL8038pr.shtml
https://www.youtube.com/watch?v=2N6cjGS7lUE
Analog by Design with Bob Pease, from National Semiconductor back in the 90s. Yeah, the video quality is pretty bad, but still great stuff worth watching.