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  1. #1
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    Wrong output in HSpice

    Hi
    I am new to HSpice and simulating a simple CMOS inverter, the netlist is as follows,
    Code:
    Inverter Circuit
    
    M1 OUT IN VDD VDD CMOSP L=0.18u W=1.8u
    M2 OUT IN 0 0 CMOSN L=0.18U W=0.9U
    VDD VDD 0 1.8
    VIN IN 0 0 PULSE 0 1.8 2n .5n .5n 7n 20n
    CLOAD OUT 0 20fF
    
    .OPTIONS LIST NODE POST
    .TRAN 200p 20n
    .PRINT TRAN V(IN) V(OUT)
    .LIB "tsmc_018um_model" CMOS_MODELS     
    .END
    when I simulate it using HSPICE J-2014.09-SP2 all is well, output is coming as expected in CosmosScope
    Click image for larger version. 

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    also in avanwaves output is coming as expected,
    Click image for larger version. 

Name:	J2014avanwaves.png 
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ID:	158597

    but in my another lab where HSPICE L-2016.06-SP1 is installed, simulating the same netlist with HSPICE L-2016.06-SP1 output on cosmosScope is comming like this,
    Click image for larger version. 

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    even on changing the x-axis to (0 to 20n) the output is,
    Click image for larger version. 

Name:	L2016cosmosScope1.png 
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    on avanwaves when i try to open the .tr0 file it gives error,
    Click image for larger version. 

Name:	L2016avanwaves.png 
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ID:	158601

    I am unable to figure out what is happening,
    please help me
    thanks in advance

    - - - Updated - - -

    Actually I have to work in HSPICE L-2016 so please help me getting the correct output.
    thanks

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  2. #2
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    Re: Wrong output in HSpice

    Maybe the problem is "another lab" and not the software
    version. Inspect the log file for warnings about missing
    .LIB target. Inspect the target model files to be sure they
    are where and what you think they are.



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  3. #3
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    Re: Wrong output in HSpice

    Yes sir I have ensured that the LIB file is OK, actually yesterday night I simulated with HSPICE L-2016 in my first lab, actually both labs has HSPICE L-2016 but still no luck the same wrong output. Then I simulated on three different computers with same netlist and model files but HSPICE J-2014 gives correct output and HSPICE L-2016 wrong output. And no body in the lab including the instructors is able to fix the problem.

    please help me
    thanks



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  4. #4
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    Re: Wrong output in HSpice

    Looking at your 3rd scope image... Its scale markings do not look the same as the other scope scales. Its time frame appears to be seconds, not nanoSec.

    As something to try...
    Rather than import the old netlist drawn in the old version...
    Draw the same circuit new in the version of software you say you must work in. Its netlist possibly has some subtle differences.

    Simplify it as much as you can. It may help if you start with a more basic circuit, and get the timeframe correct, and the tilmestep correct, and the scope scale correct. Etc.
    Then add components.

    Every simulator has its quirks. Software developers seem to avoid making their program easy to use. (Notice that your instructors cannot find the problem?) Of course software writers need to compete and add features that users demand. One has to be a longtime user to get to know the quirks.



  5. #5
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    Re: Wrong output in HSpice

    no luck please help



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  6. #6
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    Re: Wrong output in HSpice

    CLOAD OUT 0 20fF
    Is the load a capacitor by itself? That can give a simulator trouble.

    Try changing the load to a resistor. Compare the simulator results. See if the problem goes away.

    Then change the load to series RC. Compare all simulator results.



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