• State Resolved
  • Locked Locked
  • Replies 10 replies
  • Answers 1 answer
  • Subscribers 47 subscribers
  • Views 2502 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

LM675: About TO-220 (NDH) PKG

Hide
Guru 21045 points

Part Number: LM675
Other Parts Discussed in Thread: LM1875

Hi Team,

 

I have two questions of TO-220(NDH) PKG.

 

------

[Q1]

We would like to know the difference between " LM675T/LF02 " and " LM675T/LF05 ".

Could you please let us know if you have any information?


------

 

[Q2]

We would like to use heatsink for TO-220(NDH) PKG.

Could you please let us know if you have any application note of thermal design?


------

 

Regards,

Kanemaru

  • 0
    TI__Genius 11135 points

    Kanemaru

    The LF02 and LF05 suffixes are to indicate Lead Free status. Functionally they are identical.

    You asked about heatsinking information on the NDH package however the mechanical drawing you included is the NEB package.

    For the NDH (Vertical Mount) package I can't do better than the discussion on page 8 of the data sheet.

    For the NEB (Horizontal Mount-Tab Mounted to pcb) here is a detailed discussion of pcb thermal characteristics:

    Topic 10 - Thermal Design Consideration for Surface Mount Layouts .pdf

    Regards

    Dennis

  • 0 in reply to Dennis Goeke
    Guru 21045 points

    Hi Dennis-san,

     

    Thank you for your prompt reply.

     

    [Q1’]

    I understand that the LF02 and LF05 suffixes are to indicate Lead Free status and Functionally they are identical.

    What is "status"?

    (For example, Any version or spec or management practice etc.)

     

    [Q2’]

    I sincerely apologize for having caused any confusion.

    My question is about NEB (Horizontal Mount).

     

    Thank you for the document.

    However, we would like to know the Heatsink information for TO-220 Horizontal Mount TYP(NEB PKG).

    (For example, recommended Heatsink, Installation method, important point etc.)

     

    Do you have this information?

    If yes, could you please let us know the information?

     

    Regards,

    Kanemaru

  • 0 in reply to Hide
    TI__Genius 11135 points

    Kanemaru

    There doesn't appear to be any difference between the two parts. There was no change as far as die revision or specification that I can find.

    The NEB package is meant to be mounted directly to the pcb, not to a heatsink. The pcb copper is used to dissipate the heat. How large the copper plane needs to be depends on how much power the part is dissipating. The pdf I sent provides the calculations needed to determine the size needed.

    There are some general rules:

    Bigger is better. The more copper the part connects to, the more heat can be dissipated. Copper thickness is important also; 1 ounce copper is typical, but it's possible to get any thickness up to 20 ounce or more.

    Soldering the part down is best, but heat sink grease and(or)thermal insulators may be used if bolting it down.

    We often use vias from the top to the bottom so that both sides of the board may be used to dissipate heat. The more the better.

    If board size is an issue, there are surface mount heat sinks available. There are a variety of types and sizes available but here's an example:

    Be sure to check the Aavid catalog available on that page. It has a very good section on selecting a heat sink...

    I clicked the TI Thinks resolved button accidentally. Just reply to this thread if you need more information.

    Regards

    Dennis

  • 0 in reply to Dennis Goeke
    Guru 21045 points

    Hi Dennis-san,

    Thank you for the detail information.

    I greatly appreciate your cooperation.

    Regards,

    Kanemaru

  • 0 in reply to Hide
    TI__Genius 11135 points

    Kanemaru

    I have an update on the difference between the /LF02 and /LF05 versions of this part. One of my coworkers that was with National Semiconductor searched for additional information and was able to find the answer.


    It seems they have different staggers on the pins.

    The LF02 version is the one shown in the data sheet as NEB.

    The LF05 version is still a surface mount, but the pins are bent differently. Instead of pins 2 and 4 having the more acute/near right angle bend through the pcb, this one has pins 1, 3 and 5 with the acute bend through the board. Here is the mechanical drawing for the /LF05:

    mpsf028.pdf

    This difference would be important for your pcb layout...

    Regards

    Dennis

  • 0 in reply to Dennis Goeke
    Guru 21045 points

    Hi Dennis-san,

     

    Thank you for the information.

    I understand that The LF02 version is the one shown in the data sheet as NEB.

     

    Unfortunately, I can’t open URL(mpsf028.pdf).

    Would you send a different URL?

    I would like to know the MECHANICAL DATA of /LF05.

     

    Regards,

    Kanemaru

  • 0 in reply to Hide
    TI__Genius 11135 points

    Kanemaru

    We also discovered that the LM1875 Audio Amplifier uses the same package designators and has both of the mechanical drawings in the data sheet. You can find it here:

    Regards

    Dennis

  • 0 in reply to Dennis Goeke
    Guru 21045 points

    Hi Dennis-san,

     

    Thank you for the information.

    I confirmed the datasheet of LM1875 but can’t understand the different of LF02 and LF05.

    I understand that LF02 is NEB0005B and LF05 NEB0005E.

    Is my understanding correct?

    If yes, could you please let us know the different of NEB0005B and NEB0005E.

     

     

    Regards,

    Kanemaru

  • 0 in reply to Hide
    TI__Genius 11135 points

    Kanemaru

    You care correct, /LF02 is the B version and /LF05 is the E version.

    On the B version pins 2 and 4 are bent down closer to the body of the part and pins 1, 3 and 5 extend out a little further before bending down.

    The E version is just the opposite; pins 1, 3 and 5 bend down closer to the body of the part than pins 2 and 4.

    Regards

    Dennis

  • 0 in reply to Dennis Goeke
    Guru 21045 points

    Hi Dennis-san,

    Thank you for kind support.

    I understand. Thank you very much.

    Regards,

    Kanemaru