IR2110 problems

Discussion in 'The Projects Forum' started by chicheme, Aug 26, 2009.

  1. chicheme

    Thread Starter New Member

    Jun 25, 2009
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    Hi I've been having similar troubles with the IR2110 as well

    I've attached the schematics that I'm using now.

    I would like to know if someone sees any mistake. I'm using TTL of 3,5Vpp and 1 KHz at HIN and LIN and I'm getting a DC voltaje at LO arround 14 volts and 0 volts at HO.

    I hope you can help me

    Thanks
     
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  2. beenthere

    Retired Moderator

    Apr 20, 2004
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  3. chicheme

    Thread Starter New Member

    Jun 25, 2009
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    Oh, thanks
     
  4. Tahmid

    Active Member

    Jul 2, 2008
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    25
    Hi chicheme,
    I see two problems with the circuit.
    1) The SD pin is left floating. It should be connected to ground to enable operation of the chip.
    2) When you apply 15v to VDD of IR2110, you are expected to apply at least 12vpp to the logic inputs. Look at fig 12b of the datasheet where you can see that for 3vpp input you need to provide about 2.x volt to the VDD pin. But applying such little voltage to the VDD pin causes the IR2110 to become unstable. So you are better off making a discrete transistor amplifier to amplify the 3v signal to atleast 6v. Then apply about 5v to the VDD pin. I think your circuit will then work.
    PS check the datasheet carefully, there are very important data shown in the graphs and figures not written anywhere else.
    Thanks.
     
  5. chicheme

    Thread Starter New Member

    Jun 25, 2009
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    thanks Tahmid, I will try the changes that you suggested to see if it works.
     
  6. chicheme

    Thread Starter New Member

    Jun 25, 2009
    5
    0
    Hi

    I the necesary changes to the circuit (see the attachment), and for HIN and LIN I'm using 8Vpp now and 15V for Vdd, according to the figure 12b in the datasheet.

    I'm using a signal generator for the input, I'm using a square wave and I can change it to anyway I want. For the load I'm using a 100Ω resistor just to test, but I still get nothing at the exit of the IR2110.

    Can It be the voltages of the capacitors? I didn't understand the calculations of the application note, so I just picked the same value that they used in the application note, but I didn't checked the voltage of them. :confused:

    thanks for all the help!
     
  7. Tahmid

    Active Member

    Jul 2, 2008
    344
    25
    Hi,
    I'd say use 10uF for C3 and C4. The rest seems okay. Instead of checking output at IR2110, check output at the 100ohm load and watch the waveform across it. To just check output of IR2110, remove the MOSFETs, connect Vs to gnd and then check. Later rewire the circuit again with the MOSFETs and remove the jumper from Vs to gnd.
    Hope this helped.
     
  8. chicheme

    Thread Starter New Member

    Jun 25, 2009
    5
    0
    Hi, I've a question, should I use a separated ground for the SD pin.
    Like a logic ground and a power ground.??

    Thanks
     
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