ir2110 problems

Discussion in 'The Projects Forum' started by stylediva, Dec 9, 2011.

  1. stylediva

    Thread Starter Member

    Dec 6, 2011
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    i am using ir2110 for the dc motor driver..but the ic is getting hot..help??
     
  2. SgtWookie

    Expert

    Jul 17, 2007
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    Post the schematic of your circuit (not just copied out of the datasheet - YOUR circuit with all the values you used) and the layout of your circuit, or photos of the layout.
     
  3. stylediva

    Thread Starter Member

    Dec 6, 2011
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    this is the circuit i am using..but its not working..can u plz tell me the mistakes???...:(
     
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  4. praondevou

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    Jul 9, 2011
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    [​IMG]
     
  5. stylediva

    Thread Starter Member

    Dec 6, 2011
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    i am using the vdd=5v from protoboard..wat shud i do???...
     
  6. praondevou

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    Jul 9, 2011
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    5Vdd should be ok. datasheet: IR2110

    Did you see the missing connections from Vs to the source of the upper MOSFETs?
     
  7. hgmjr

    Moderator

    Jan 28, 2005
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  8. Lundwall_Paul

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    Oct 18, 2011
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    What is purpose of the diodes in parallel with the 22 ohm resistors?
     
  9. praondevou

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    They provide a fast turn-off of the MOSFETs. The gate is being charged through the 22R resistor and discharged through the diode (and partially through the resistor when the diode stops conducting, but at this moment the MOSFET has already turned off)
     
  10. SgtWookie

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    Jul 17, 2007
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    It's necessary for the MOSFETs to get some "extra help" in turning off quickly, as an idiosyncrasy of MOSFETs is that they turn ON more quickly than they turn OFF.

    This is a real problem in H-bridges, as one side (high or low) needs to be turned off before its complement turns ON, or there will be a "shoot through" condition; where the power supply is shorted out via the path through the high and low side MOSFETs.

    The resistor is necessary as a "snubber" to keep the MOSFET gate from "ringing" excessively. The wire from the driver to the MOSFET gate has inductance, and the MOSFET gate acts as a small capacitor. This creates a series LC circuit that will ring like a bell struck with a hammer when the gate toggles from one state to the other.
     
  11. stylediva

    Thread Starter Member

    Dec 6, 2011
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    sorry for the mistakes in connection..actually i 4got to draw that connection.. i have done all the connections..plz tell me that all the values of the capacitors that i m using are right or is there anything to change??..i am applying 5vp-p. and i m giving PWM from AVR microcontroller..and inverting PWM from schmitt trigger thru RC network at its input..i m attaching full schematic.plz tell me the mistakes in that.
     
  12. stylediva

    Thread Starter Member

    Dec 6, 2011
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    also tell me shud i use ceramic capacitors or the mentioned ones are ok??..and i use normal diodes..shud they be schottky???..
     
  13. stylediva

    Thread Starter Member

    Dec 6, 2011
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    plz tell me that all the values of the capacitors that i m using are right or is there anything to change??..i am applying 5vp-p. and i m giving PWM from AVR microcontroller..and inverting PWM from schmitt trigger thru RC network at its input..i m attaching full schematic.plz tell me the mistakes in that.
     
  14. praondevou

    AAC Fanatic!

    Jul 9, 2011
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    1. What is the PWM frequency/duty cycle?

    2. If the capacitor at the 74HC74 input is really 10uF then there will be no inverting PWM signal. Therefore the lower left and upper right MOSFET will not be switching. (or in an unpredictable manner) Since the lower left MOSFET will not be switching the bootstrap capacitor won't be properly charged, so the upper left MOSFET will also be doing nothing.

    If this RDC at the 74HC14 was supposed to introduce an additional deadtime the circuit needs to be changed.

    For both signals that go to the IR2110s the rising slope needs to be delayed.
    [​IMG]
     
    Last edited: Dec 11, 2011
  15. praondevou

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    Jul 9, 2011
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    One thread is enough. Please stay in the other thread.
     
  16. bertus

    Administrator

    Apr 5, 2008
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    Hello,

    I merged the threads.
    The posts show up in the following of posting.

    Bertus
     
  17. stylediva

    Thread Starter Member

    Dec 6, 2011
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    thank u so much for ur help..its a great help..:)
    plz tell me that the rest of the circuit is ok??..or is there any mistakes in the values of capacitors??...or anythng else..??..
     
  18. praondevou

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    What is your PWM frequency and min/max duty cycle?
     
  19. stylediva

    Thread Starter Member

    Dec 6, 2011
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    i will generate the PWM from AVR with the frequency u mentioned that is 10khz and also i can adjust the duty cycle..u guide me wat shud i do..??..plz..if i take 50% duty cycle which changes shud i need to do in ur ckt..???..
     
  20. stylediva

    Thread Starter Member

    Dec 6, 2011
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    the PWM frequency of my controller is 4khz..and 50% duty cycle..tell me the changes according to that..plz..
     
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