What is the difference between an LM78L05 and a L78L05

[bigdaddymrx]

I have a few L78L05 regulators and my project calls for an LM78L05.  Can anyone tell me the difference if there is any?

[Luke51411]

I believe they have opposite pinouts, they'll work the same if that is taken into account I believe.

[alanp]

I'm guessing you mean 7805 and 78L05?

The major difference (besides pinout -- always check pinout in the datasheet!) is current handling. The TO-92 package one does not have the cojones of the TO-220 one.

[bigdaddymrx]

No I mean LM78L05 and a L78L05. only the "M" is not present on the ones I have.  I also have a couple L7805CV ones too.

[jimilee]

No I mean LM78L05 and a L78L05. only the "M" is not present on the ones I have.  I also have a couple L7805CV ones too.

Yeah, the pinouts are reversed, search the data sheets.


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[bigdaddymrx]

I checked the data sheets and the pinouts are the same for both.

[jimilee]

I checked the data sheets and the pinouts are the same for both.

Sorry if I came across as a dick, wasn't my intention. Any way on the LM Pin 3 is the out on the L, Pin 1 is the out.

[mgwhit]

On the datasheets I looked at the L78L05 TO-92 is shown in bottom view and the LM78L05 TO-92 is shown in top view.     Annoying, but probably accounts for the disagreement.  I thought they were the same for a few minutes, too. 

[Never mind -- I was misreading the TI datasheet.]

[RobA]

Yikes! Those two data sheets are trying to be as confusing as possible! My reading is that both show the TO-92 package from bottom view and the pinouts are the same.

My recommendation for these voltage regulators is to always check the specific data sheet from the manufacturer of the part you've got.  I've popped a couple myself putting them in backwards when I didn't.

[RobA]

Oh, to try to answer your original question, the main difference between the voltage regulators that we usually care about is the current handling. The LM78L05 is a typical 100mA regulator and if you have one that'll handle that, you should be good.

The other two specs that can be important are the dropout voltage and the noise figures for the regulator. Again though, since what's called for is a LM78L05 and I'm guessing that this is going in a 9V circuit, neither of these is probably critical either.

[bigdaddymrx]

No need to apologize jimilee I wasn't thinking that at all.  I was just as confused as I could be with this pinout situation.  I'm thinking I could just rotate the L78L05 and it should work in place of the LM78L05.  What do you all think?

[jimilee]

Yep, well usually, depending on the voltage.


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[RobA]

No need to apologize jimilee I wasn't thinking that at all.  I was just as confused as I could be with this pinout situation.  I'm thinking I could just rotate the L78L05 and it should work in place of the LM78L05.  What do you all think?

Who is the manufacturer of the regulator that you have?

My reading of the two spec sheets posted earlier is that they have the same pinouts.

[bigdaddymrx]

I don't know who made them.  There from Tayda.  They have L78L05  CE 144   and some wierd looking symbol in the upper left corner.

[RobA]

I don't know who made them.  There from Tayda.  They have L78L05  CE 144   and some wierd looking symbol in the upper left corner.

The only one Tayda lists is the ST micro part. That goes wit the data sheet that Matt linked to above. You can't always be sure with Tayda because they see what they can get at the time, but it likely is the ST part.

I read the two data sheets as having the same pinout. They both have confusing figure captions, the TI sheet has the diagram way offset from the caption and it looks like it goes with the caption above but it goes with the one below.

From what I read, the two figures for the TO-92 package are from the bottom with the output pin to the left when the flat face of the regulator is up. I think they are the same. Most of the pinouts for these are the same, so this is consistent with that. There are some weird ones though.