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Welcome, Guest. Please login or register. Did you miss your activation email? This topic This board Entire forum Google Bing. Print Search. Ghydda Regular Contributor Posts: 91 Country:.
Hi everyone, I am having difficulties coming up with suitable search terms in Google for locating an alternative part.
In my application it is reducing a 12V supply rail to 3. For my application the LM excels in a few areas: no thermal shutdown protection very low cost common as mud multiple distributors and manufactures did I mention it is cheap?
However, for my application the LM has these undesired traits: a high minimum load to maintain regulation somewhat high-ish reference pin current Is there such a part, which has better performance than the LM regarding the undesired traits, yet does not compromise too much on the positive traits? If we learn from our mistakes then I reckon I'm getting a great education! Quote from: Ghydda on March 08, , am. Quote from: Ghydda on March 08, , pm. Hey there If I may ask , is your application battery or mains supply?
Have you thought of using a buck regulator? Those you can get with a stand by current of a few micro Amps and they are over all more efficient. Most don't even need cooling? I use them for various applications. Best regards. What about LT? Quote from: zlymex on March 08, , pm. If you mean you really want it in the same soic-8 package you don't want to redesign your pcb , just dig up some more And I agree with others, you could make a switching regulator in pretty much the same footprint.
Get something like a LM and a couple of ceramic capacitors and diodes and an inductor and a couple of resistors to set the voltage to 3. We use a bunch of MCPA, but will require a board respin. Quote from: 8of Siwastaja Super Contributor Posts: Country:. Quote from: Ghydda on March 09, , am.
It's hard to find "no thermal protection" chips anymore. If you really need to operate it at high temp, you should consider spend x the cost to replace everything to high temp certified parts before your device fail and kill someone. Reconsider LML. The quiescent current is probably not as high as you fear.
The ADJ pin current is only typically 0. So if you can guarantee that the load will always be at least 2. If you fear going unregulated due to low load at startup for example , then an additional shunt such as a zener could be used to limit the voltage. Quote from: Siwastaja on March 09, , am.
Quote from: Ghydda on March 09, , pm. Quote from: mmagin on March 09, , pm. So, You are designing a safety-related product and seemingly have no clue what you are talking about, let alone some logical thinking?
I'm horrified. If the product needs to run as long as possible in a fire, consider designing it so, properly look for thermal insulation and evaporative cooling, for example!
Just having no thermal protection in the regulator allows it to run only very slightly hotter before self-destructing. The protection level is very near to the thermal runaway and self-destruction.
The stuff behind the regulator will likely stop working anyway. As you are running low current, the regulator won't heat up internally much so die temperature will be close to ambient temperature, and the thermal protection will work at temperatures above the rating of most microcontrollers, for example.
So your circuit has most likely already failed at the time the ambient heats up the regulator over the protection threshold. Sure, you may not need thermal protection in the regulator, but not having one will not help you the slightest, as you seem to think. I think this "lack of thermal protection" thing is giving you a false sense of security.
Howardlong Super Contributor Posts: Country:. Quote from: blueskull on March 09, , pm. There was an error while thanking. SMF 2. EEVblog on Youtube.
LM317L regulators. Datasheet pdf. Equivalent
LM317LM/NOPB - Linear voltage regulator 1.2...37 V SO-8, LM317, Texas Instruments