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NE555: LTSPICE model for NE555 IC

Part Number: NE555
Other Parts Discussed in Thread: TLC555, TINA-TI

Hello I am using the NE555 timer IC in a design and I would like to simulate its behavior first. Do you by chance have the LTSPICE model for the part NE555?

Personal email is <email address removed>

Work email is <email address removed>

Thank you,

Johnathan Williams

  • Hello Johnathan,

    We do not have a model for NE555. The TLC555 timer which is an upgraded timer does have a model in the product folder.

  • Hello Ron, I'm using the TLC555 Timer in my LTSPICE simulation. At first I was receiving an error stating "Can't resolve .PARAM NZ = {0.3/(VT*LOG(1 + 5.0M/ISZ))}". I researched this error online and found that the thermal voltage "VT" did not have a .PARAM statement defined. So I added a statement: ".PARAM VT=.026". I ran the simulation a second time. It finished and plotted the desired waveforms yet unfortunately in the SPICE ERROR LOG file I received the following errors shown below from the SPICE ERROR LOG. Unfortunately I fear that I won't be able to rely on these results due to the SPICE simulator ignoring several MOSFET parameters. Is there a workaround for this to get accurate results?



    Error on line 11475 : .model tlc55x_pmosd_hv pmos level=3 l=10u w=100u kp= 3e-005  vto= -0.85  lambda=2e-3 theta=2.2e-01  cj= 0.00024  cjsw= 1.76e-009  cgso= 3.3150180477024e-011  cgdo= 3.3150180477024e-011  rsh=10 pb=0.65 ld=70n tox= 1e-007
        * Unrecognized parameter "lambda" -- ignored
    Error on line 11462 : .model tlc55x_nmosd_hv nmos level=3 l=10u w=100u kp= 6e-005  vto= 0.8  lambda=2e-3 theta=1.8e-01  cj= 0.000144  cjsw= 8e-010  cgso= 3.3150180477024e-011  cgdo= 3.3150180477024e-011  rsh= 10 pb=0.65 ld= 70n tox= 1e-007
        * Unrecognized parameter "lambda" -- ignored

    Instance "m:u9:mn10:1": Length shorter than recommended for a level 1 MOSFET.

    Direct Newton iteration failed to find .op point.  (Use ".option noopiter" to skip.)
    Starting Gmin stepping
    Gmin = 10
    vernier = 0.5
    Gmin = 2.07126
    vernier = 0.25
    vernier = 0.125
    vernier = 0.0625
    vernier = 0.03125
    Gmin = 1.99293
    vernier = 0.015625
    vernier = 0.0078125
    vernier = 0.00390625
    vernier = 0.00195313
    vernier = 0.000976563
    Gmin = 2.00068
    vernier = 0.000488281
    Gmin = 0
    Gmin stepping failed

    Starting source stepping with srcstepmethod=0
    Source Step = 3.0303%
    Source Step = 33.3333%
    Source Step = 51.5152%
    Source Step = 59.0909%
    Source Step = 66.6667%
    Source Step = 74.2424%
    Source Step = 81.8182%
    vernier = 0.375
    Source Step = 90.5303%
    Source stepping succeeded in finding the operating point.


    max_output_voltage: MAX(v(v_meas1))=4.02539 FROM 0 TO 20
    max_output_voltage2: MAX(v(v_meas2))=3.41004 FROM 0 TO 20

    Measurement "max_output_voltage3" FAIL'ed

    Measurement "max_output_voltage4" FAIL'ed

    Measurement "voltage_change" FAIL'ed

    Measurement "max_power" FAIL'ed

    Measurement "max_comp_current" FAIL'ed

    Measurement "min_comp_current" FAIL'ed


    Date: Tue Apr 14 10:14:55 2020
    Total elapsed time: 1.949 seconds.

    tnom = 27
    temp = 27
    method = modified trap
    totiter = 24167
    traniter = 21459
    tranpoints = 8182
    accept = 5943
    rejected = 2239
    matrix size = 205
    fillins = 201
    solver = Normal
    Thread vector: 54.0/28.3[6] 18.1/7.9[6] 7.4/5.4[6] 0.8/10.9[1]  2592/500
    Matrix Compiler1:     954 opcodes  8.5/[4.0]/4.3
    Matrix Compiler2:    1490 opcodes

    Thank you,

    Johnathan Williams

  • Hi Johnathan, 

    Sorry to hear that you're having issues. We're not too familiar with LTSPICE simulator. 

    Can you try this on TINA-TI and let us know if you're having any issues? You can download the software for free from: http://www.ti.com/tool/TINA-TI

    Regards,

    Bala Ravi

  • Hi Johnathan, 

    I hope your issue is resolved. If not, please follow-up here. I will go ahead and close this thread for now. 

    Regards,

    Bala Ravi