Different LM317/337s

[belyakove]

I'm looking to buy some LM317s and LM337 for my power supply but I can see that there are a lot of different options available from different manufacturers for completely different prices. Like 10 times price difference. Even from single manufacturer there are different variations of these chips and I can't get what's the difference.
For instance from TI there are LM337T and LM337KCS available but I don't see what is the difference and what should I choose.
Also there are options from ST and ON Semiconductors that seem to be 5 times cheaper then TI. And all of these are TO-220 package.
What is the difference and what should I choose?

 

[AndrewT]

There are low power/current and medium power/current and high power/current.
The To220 version falls into the medium power/current, with a maximum output around 1.5A to 2A
The datasheet for each manufacturer will give the codes that apply to each category.
And codes for lots of other parameters. Usually these others can be ignored for our circuits.

 

[jgf]

Search for the thread " Another look at the lm317 / lm337 regulators" where jbau does extensive testing including different makes.

 

[fabrice63]

For the positive , the 317 AT/NOPB is the better , and for the negative , choose the 237 KCSE3 , they both have an better line regulation .


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[dotneck335]

For low voltage/power applications (~≤ +/- 18 volts, ≤ 2 amps), the best 3-pin regulators are from Linear Technology---their LT317 (+) and LT337 (-). These offer the best ripple rejection (≥80 db) and lowest noise (0.001%) of any manufacturer of these type regulators. They are a bit more expensive (~$2.50 each), compared to the T.I. ones (~ 50¢ each) but well worth it. Arrow Electronics carries them and offers free shipping.