MCP8024 help

Discussion in 'The Projects Forum' started by chrisw1990, Dec 8, 2013.

  1. chrisw1990

    Thread Starter Active Member

    Oct 22, 2011
    543
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    Can anyone help?
    found this chip on microchip, but dont understand what the FG and Rprog pins do, despite reading the description on the datasheet.. would like to use them for a small bldc motor for a quadcopter..

    Datasheet on Microchip:
    http://ww1.microchip.com/downloads/en/DeviceDoc/20002281B.pdf

    Motors to be used are potentially this:
    http://hobbyking.com/hobbyking/store/__9663__HobbyKing_AP_03_7000kv_Brushless_Micro_Motor_3_1g_.html
    or this:
    http://hobbyking.com/hobbyking/store/__9068__Turnigy_1220_Brushless_Inrunner_Motor_10300kv.html
    i suspect the latter as it could be fit into a hubsan frame without too much modification i suspect.
    please help!
    Cheers,
    Chris

    Correction - The link is for MTD6505, i got the title wrong!! edited 2209
     
    Last edited: Dec 8, 2013
  2. MaxHeadRoom

    Expert

    Jul 18, 2013
    10,520
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    The link is for a MTD6505 not a MCP8024?
    Which are you using?
    Max.
     
  3. chrisw1990

    Thread Starter Active Member

    Oct 22, 2011
    543
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    Sorry, i was looking at both as the 8024 has built in regulators,
    i mean the MTD6505 due to its small size and external components, sorry!
     
  4. chrisw1990

    Thread Starter Active Member

    Oct 22, 2011
    543
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    *bump*
    anyone? :(
     
  5. BobTPH

    Active Member

    Jun 5, 2013
    782
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    FG is an open drain output to signal the fan speed, presumably by the frequency of pulses. If you don't need it just don't connect anything to it. If you do need it use a pullup of 10K or so to Vdd and take the output from FG.

    Rprog is programming the back EMF of the fan. Section 4.9 tells you how to determine this by blowing air through the fan and looking at what it outputs on an oscilliscope. You then look up the computed Km and use the resistor from table 4-2 to ground.

    Hope this helps.

    Bob
     
    chrisw1990 likes this.
  6. chrisw1990

    Thread Starter Active Member

    Oct 22, 2011
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