Re: Circuit suggestion for an current limited power supply application
Hi,
Instead of a resistive divider use a voltage reference IC like the TLV431 or the TL431, or any by any manufacturer you find with similar or better specs.
I see no problem with the 646x op amps for a DC (static voltage) current source, they do their job well at low frequencies andd operate up to about 16V. The "better" the op amp, the greater the cost and a Ferrari OA is likely unnecessary here. Op amps are like screwdrivers, don't you think, each serves a purpose, some can cover various needs, some are unsuitable for certain circuits - that's what hateful in-depth and confusing OA datasheet perusals and comparisons are for. Certainly adds new meaning to the expression "No pain, no gain."
100ppm resistors are not especially expensive and won't eat into your budget noticably, 50ppm and lower may begin to feel a painful consideration and unnecessary I would say.
The LM334 is one current source IC, and the datasheet is good for tips on reducing temperature variations.
I'd observe results experimentally with the temperature feature of a simulation tool to compare various current source circuits to see which is closest to your real needs.
Is this current limiting you are after or a current source/sink?