Re: Problems with SPICE models from vendors

From: Robert Baer (robertbaer_at_earthlink.net)
Date: 03/26/05 

Date: Sat, 26 Mar 2005 04:01:32 GMT

Helmut Sennewald wrote:

> "Robert Baer" <robertbaer@earthlink.net> schrieb im Newsbeitrag
> news:%v01e.3960$gI5.2228@newsread1.news.pas.earthlink.net...
>
>>Helmut Sennewald wrote:
>>
>>
>>>----- Original Message -----
>>>From: "Jim Thompson" <thegreatone@example.com>
>>>Newsgroups: sci.electronics.cad
>>>Sent: Friday, March 25, 2005 3:37 PM
>>>Subject: Re: Problems with SPICE models from vendors
>>>
>>>
>>>
>>>
>>>>On Fri, 25 Mar 2005 09:26:21 GMT, Robert Baer
>>>><robertbaer@earthlink.net> wrote:
>>>>
>>>>
>>>>
>>>>> The LM324 model from TI works fine,but the one from National
>>>>>Semiconductor is junk.
>>>>> I tried numerous Analog Devices models for various rail-to-rail
>>>>>opamps, and found that almost all i tried gave me the same kind of
>>>>>cryptic square root error.
>>>>> Those tried: AD8605, AD531, AD541, AD8552, and the AD8571; the only
>>>>>one tried that did work was for the AD8614.
>>>>> Now i would dearly like to have a set of models that were known to
>>>>>work (and more or less correctly), but i need to get a working AD8605
>>>>>model.
>>>>> The sets i have came from the manufacturer created in the latter of
>>>>>1992, and thus are not quite up-to-date.
>>>>> However, the model for the AD8605 was downloaded via the web just
>>>>>yesterday - implying the problem is not fixed.
>>>>>
>>>>> Can anyone help?
>>>>
>>>>Problem noted, and forwarded to the appropriate device-modeling
>>>>manager at Analog Devices.
>>>
>>>
>>>Hello Jim,
>>>this wasn't necessary. This AD8605 model runs without any
>>>convergence problem in LTspice. So the model doesn't have any error.
>>>Yuu should withdraw your email to AD and apologize to the manager
>>>you have contacted for any inconvenience. :)
>>>
>>>Best Regards,
>>>Helmut
>>
>> Please tell me why it does not work (and others mentioned) and that the
>>model for the AD8614 does work.
>> I am using a DOS version of TopSpice.
>> And look at an earlier posting where i clearly show that the AD8614
>>model gives large input currents and a large Vos.
>
>
> Hello Robert,
> please tell me who said that the Ad8605 model doesn't work?
> Maybe TopSpice has problems with this opamp whereas other SPICE
> variants don't have a problem with the AD8605.
> The different SPICE versions on the market are far off from the
> original SPICE program code.
>
> Best Regards,
> Helmut
>
>
   I said that the AD8605 model does not work; at least for the old DOS
TopSpice.
   Based on raw experience.
   Found the same model appears to work in Switchercad3 which i recently
downloaded.
   See previous recent postings by me; there are nasty errors in a
simple amplifier circuit using the AD8605.