pspice error..

Discussion in 'Programmer's Corner' started by remshad, Jul 5, 2010.

  1. remshad

    Thread Starter New Member

    Aug 14, 2009
    3
    0
    please tell me to solve this error
    while am doing a communication project simulation an error coming..
    its a voltage divider...



    i have attached the screen shot of the error..
     
  2. retched

    AAC Fanatic!

    Dec 5, 2009
    5,201
    312
    You would be better off cutting and pasting the code, rather than making us type it in from a screen shot.

    Copy your spice code, and paste it here using the [C0DE] [/C0DE] delimiters.

    OR

    Click on 'Go Advanced', It is the button next to 'Post Quick Reply'.
    On the top bar of the Advanced Editor there is a '#' button.
    Click the '#' button then PASTE your code by pressing 'Ctrl-V' (Option-V on Macs)
     
  3. Eng_Bandar

    Active Member

    Feb 27, 2010
    50
    1
    I think problem in connection.
    Check your connection
     
  4. JoeJester

    AAC Fanatic!

    Apr 26, 2005
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    You only have one connection to the node called GND_Power

    There are no supplies connected to GND_Power.

    on edit ...
    Post a screen shot of your schematic pertaining to that subcircuit,
     
    Last edited: Jul 6, 2010
  5. suki

    New Member

    Jul 6, 2010
    18
    0
    this is the circuit that Remshad is talking about.. pls have a look.
     
  6. suki

    New Member

    Jul 6, 2010
    18
    0
    im giving the pulses.but the result doesnt gv me any pulses.that's strange.can somebody pls help me with this problem?
     
  7. retched

    AAC Fanatic!

    Dec 5, 2009
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    [​IMG]

    Where did you get this from?

    This is absolutely crazy.

    What are you trying to do? Tell me this, and maybe we can help.
     
  8. bertus

    Administrator

    Apr 5, 2008
    15,647
    2,346
    Hello,

    One of the mistakes is the to low resistance at the output.
    The datasheet says it must be greater than 2K.
    Change the 180 Ohms resistors (R1 and R2) to 10K each and see what happens.

    Bertus

    PS I have attached the datasheet.
     
  9. JoeJester

    AAC Fanatic!

    Apr 26, 2005
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    suki,

    First off ... that is not the same circuit as the OP's listing.

    Secondly, email is not the preferred medium for discussing these type problems, the forum is. Otherwise, no one else would benefit from the discussion.

    Lastly, where did you get that circuit?
     
  10. remshad

    Thread Starter New Member

    Aug 14, 2009
    3
    0
    am and suki is the colleague of this project..

    this circuit is a voltage divider and for a wireless communication project (doing in college)
    thank you bertus,JoeJester for your generous support...
    we are now doing its in pspice for simulation ,let u show whats the current status of design (may suki tell ) after doing the above modification...

    (imp:we are beginner in the field of pspice design so ..am expect generous and detailed explanation )
    thanks
     
  11. suki

    New Member

    Jul 6, 2010
    18
    0
    thanks all for the reply.

    first of all, actually, I design it myself. I need to connect the circuit with MAX232A in pspice but it is not available in pspice, so i try to feed the pulses instead.and also, i fed the circuit with 3.7v which with the voltage summer, i expect the output to be the pulses of 3.7v to 4.2v. but no pulses at all being output.

    sorry to post it here, because I don't know wherelese should I ask.
     
  12. suki

    New Member

    Jul 6, 2010
    18
    0
    this is the modifications that i've made towards the circuit.can u pls tell me what is the problem with the circuit?
     
  13. JoeJester

    AAC Fanatic!

    Apr 26, 2005
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    You do not have a voltage summing circuit, look up summing circuits and you will see your first error.
     
  14. suki

    New Member

    Jul 6, 2010
    18
    0
    sorry, about the voltage summer, i found that it is useful when i want to use with the MAX232A, so in the modification, i've get rid of it. but still couldnt get any pulses as the result.
     
  15. JoeJester

    AAC Fanatic!

    Apr 26, 2005
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    What frequency are you using?

    The frequency you are using on your simulation is way too high for that device.
     
  16. bertus

    Administrator

    Apr 5, 2008
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    Hello,

    I think JoeJester is right.
    It is stated per=100n, this means a repetition rate of 10 Mhz.
    This is to fast for the opamp.

    Slew rate: SR = 1.0 V/µs

    This means it takes 1 μS to jump 1 Volt.

    Bertus
    [​IMG][​IMG]
     
  17. suki

    New Member

    Jul 6, 2010
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    i need to work out with the frequency of 13.5Mhz because actually, I am building a break-down circuit of Near-Field Communication which is the transmitter part.
     
  18. bertus

    Administrator

    Apr 5, 2008
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    Hello,

    Then you need to look for an other opamp with a MUCH higher slewrate.

    Bertus
     
  19. suki

    New Member

    Jul 6, 2010
    18
    0
    but when I try to design it in the pspice, the component of HA17741 is not the same with the one in the datasheet. what should i connect to the OS2 and OS1 node?

    anyways, I will try to change the op-amp too.
     
  20. bertus

    Administrator

    Apr 5, 2008
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    Hello,

    Here is a list of national highspeed opamps.
    (remove the .txt and open it in excel).

    Bertus
     
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