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.20 cent mosfets with no data sheet — Parallax Forums

.20 cent mosfets with no data sheet

metron9metron9 Posts: 1,100
edited 2007-02-16 22:31 in General Discussion
I can't find a data sheet for this part and digikey has 15,000 of them. I bought a few but I have tried all the usual searches to find it.


Digikey # 64-8037PBFCT-ND
MFG # 64-8037PBF (international rectifier)

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Think Inside the box first and if that doesn't work..
Re-arrange what's inside the box then...
Think outside the BOX!

Comments

  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2007-02-15 18:11
    Yeah, that number comes up blank on the manufacturer's website. I would call DigiKey to see if that's the right manufacturer's part no. Most International Rectifier part numbers start with "IR".

    -Phil
  • metron9metron9 Posts: 1,100
    edited 2007-02-15 19:23
    Hi Phil, The part that I think will work the best here for the LUXEON III 1500mA LEDS is digikey# 497-4525-1-ND up to 6.5AMPS

    It has at 5V .06 OHMS . That is 60 milliohms correct? It is the smallest RDS(on) resistance mosfet I could find.
    The Gate Threshold is a volt lower but that is fine for this application.


    This one: 479-3309-1-ND
    has some nice features: Current limiting, thermal shutdown, short circuit protection and some interesting DIAGNOSTIC FEEDBACK
    I may use this in my stage lighting product. I may be using a 36V transformer with those.



    Going through the list of fets that come in sot-223 package. I bought 10 of each of these as well but I have not read the datasheets in detail yet to compare them.


    497-3177-1-ND
    IRLL024Z-ND
    497-4764-1-ND
    IRLL024N-ND


    And just because I like to buy something extra that I have no use for and can't even imagine a use for since I have some empty drawers.

    CLA220-ND a 415V

    The Drain Current specs though I don't understand , conditions of VDS=50V is 5ma current maximum, and at 5V is 130ma minimum.
    probably never use it but mostly because i don't understand its specs.


    I would appreciate any thoughts on differences in these mosfets generally, historically or specifics.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Think Inside the box first and if that doesn't work..
    Re-arrange what's inside the box then...
    Think outside the BOX!
  • metron9metron9 Posts: 1,100
    edited 2007-02-16 01:06
    Here is a picture of the mosfet chip.
    The digikey part# is 64-8037PBFCT-ND and is $1.25 qty 1

    I searched findchips , the lowest price I found qty 10,000 is 70 cents so 290 cents is 1/3 of that no qty limit
    They have 5222 in stock so its a good buy. I don't know why they are marked that way though.
    I tested the fet vs the irfl1110 , The current went from 650mA to 750mA through that fet and the specs show a .5ohm to .2ohm difference in the resistance of the chip.

    This fet says it has a .20 ohm resistance RDS(on)

    To test that I measured the voltages across the resistor and LED

    Running the LED just through the resistor is 1180mA with a 1.2 Ohm resistor

    My Voltage in is 4.6V

    Measured 1.76V across the resistor

    Measured 2.84V across the LED

    2.84 + 1.76= 4.6


    Now I put the fet in and I get: 750mA current

    0.8 Across the resistor
    2.5 across the LED
    1.3 across the FET

    So this fet is pulling (1.3 x .750) = .975 watts

    ===============================================================

    Now I tested this fet : Digikey# 497-425-1-ND
    MFG Part STN4NF03L price $1.30
    6.5A max current

    Big difference. RDS(on) is specified on the datasheet as <0.05

    I get 1150 mA just 10 mA across the fet and it doesn't even get warm about .073V across the fet

    ================================================================

    Digikey# 497-3309-1-ND price $1.30
    MFG VNN3NV0413TR

    This chip has a lower Amp Rating 3.5A but it has some nice features, thermal shutdown and short circuit protection are two of them.

    I get 1130ma through the LED using this Mosfet

    ================================================================

    497-3177-1-ND 60V 4Amp Price .97cents

    I get 1140mA through this one.

    =================================================================

    Digikey# 497-4764-1-nd 60V 4amp price .59 cents

    1110ma through this one

    ========================================

    Digikey# IRLL024Z-ND 55V 5 Amp price .78 cents

    1150ma through this one

    ========================================
    Digikey# IRLL024N-ND 55V 3.1 Amp price .64 cents

    1150ma through this one
    ========================================

    So I learned about RDS(on) resistance because I needed something better than what I had.
    I paid $1.05 each qty 100 for the IRFL110 and the .20 cent fet was better (not by much) but all of the others I just tested are much better choices. I think the rule of thumb of 2x the rating must be true as the IRLF110 is only a 1.5A but at 100C it drops to .96 and that's when pushing with 10V.

    Now I can finish my LUXEON III color test board with 8 different colors and do some thermal testing.

    Thanks to Phil for the tip on RDS(on) resistance something I had never looked at before after all, I'm not an EE but I play one when I get off work.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Think Inside the box first and if that doesn't work..
    Re-arrange what's inside the box then...
    Think outside the BOX!
    irfl4310.gif
    514 x 466 - 110K
  • GadgetmanGadgetman Posts: 2,436
    edited 2007-02-16 09:56
    Have you considered the IRF7311?
    (Two N-Channel MOSFETs in a single SO-8 package)

    It's listed with .029 Ohm.

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    Don't visit my new website...
  • boeboyboeboy Posts: 301
    edited 2007-02-16 14:27
    Here is a good chip search site http://www.findchips.com/

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    lets see what this does... KA BOOM (note to self do not cross red and black)
  • Beau SchwabeBeau Schwabe Posts: 6,568
    edited 2007-02-16 16:09
    metron9,

    try...

    http://www.alldatasheet.com/datasheet-pdf/pdf/68466/IRF/IRFL4310.html

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    Beau Schwabe

    IC Layout Engineer
    Parallax, Inc.

    Post Edited (Beau Schwabe (Parallax)) : 2/16/2007 4:14:12 PM GMT
  • metron9metron9 Posts: 1,100
    edited 2007-02-16 16:58
    After I got the chip I did find the data sheet on that site Beau. The original problem was that digikey did not list it with that part number and did not link a data sheet. What I am saying is it is a good price for that chip if you don't need low RDS resistance.

    Gadget, that's a nice chip you point out. Won't work on this though because the boards are already made using a sot-223 layout.

    It's really interesting though how critical some specifications on chips that do the same basic thing come into play for different circuits. I never realized how much power difference there could be for a resistance that is only 1/2 ohm or 1/10 of an ohm when one typically thinks of a 100 ohm resistor that could be 99 ohms or 101 ohms and makes no difference in the circuit.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Think Inside the box first and if that doesn't work..
    Re-arrange what's inside the box then...
    Think outside the BOX!
  • StarManStarMan Posts: 306
    edited 2007-02-16 22:31
    Metron9,

    Thanks for the great information.· What is the power rating on your 1.2 ohm resistors?· Do you have a part number?· I have been considering playing around with some of those high power Luxeons.· Please keep us posted on the results of your thermal testing.

    Thanks,

    Chris I.
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