LM340: LM7805MP vs LM340MP-5.0 - are there any differences in their specifications or not?

Hi Karl,

My team is looking into this. We'll get back to you in 1-2 business days.

Regards,

Nick

Hi Nick, any update? Thanks // Karl

Hi Karl,

Sorry for the delayed response. It's admittedly difficult even for us to sort out the nomenclature for some of these legacy devices. I'm unsure of which orderable part numbers are specific to the LM340A. I recommend checking out the TPS7B83-Q1 - it has substantially better performance than the LM7805 or LM340A at a similar price point, and is P2P with the LM7805MP/NOPB. 

Regards,

Nick

LM7805MP/NOPB can handle up to 1.5 A though, whereas TPS7B83-Q1 only up to 150 mA, and I need more than that; hence me asking about LM340MP-5.0/NOPB above as it is a sibling of LM7805MP/NOPB. Is there any chance you might be able to find the information given a few days? Any other parts that might be relevant?

BR//Karl

Hi Karl,

Sorry I missed that. I'll keep digging. Do you need more than 1A?

Regards,

Nick

Thanks - I haven't measured the overall +5V consumption in a while, but the total consumption on the LM7805MP supplying +12V rail is currently around 300-350 mA, and I don't think it'll increase that much going forward, so presumably no (famous last words perhaps ;)).

BR//Karl

PS. Forgot to say that if the footprint of another (better) part would be the same overall dimensions or less, I could consider updating the PCB layout as well; I'm not that tied down wrt LM7805 and its siblings in this particular case, it was just the easiest migration path to look into first.

Hi again, it turns out I may previously have been a bit mislead by your LDO regulators landing page; there are a few ultra-low-noise LDOs also for +12V input, but they're not visible from the mid-VIN tab where you'd perhaps expect to find them, but instead under the wide-VIN tab... (labeled >30V). Looking at TPS7A47 (which I think would size-wise fit as it requires few external components) among others at the moment - any thoughts?

BR//Karl

Hi Karl,

That's good to know, I normally use the "View all products" page so I've never noticed that.

If you're willing to do a layout change I would suggest doing so because the LM7805 (as well as the LM340A) are legacy devices with pretty poor performance. TPS7A47 is a good option. Is noise a key concern for you? What other key parameters do you have? I suppose if your system was fine with the LM7805 then most modern devices will be an improvement, but I can help find the best option for you if I can better understand your needs.

Regards,

Nick

Thanks Nick, yes both noise and PSRR are of higher importance for my use case as the externally fed +12V supply rail can be a bit noisy depending on the surrounding environment. I also have parts like a precision DAC, ADC etc in this particular product, so reducing noise in any form wherever I can is always a good thing. As a sidenote, I also liked the simplicity of setting the output voltage (+5V in my case) on the TPS7A47 without any external components - just connect the relevant configuration pins to GND. Good stuff!

BR//Karl