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AN: Basic OpAmp Output Stage Spice Model Posted to my Website

Started by Jim Thompson January 9, 2016
Basic OpAmp Output Stage Spice Model... Passes load current to proper
Voltage Rail... No Voltage Bounds, No Current Limit, Yet ;-)

See... 

    BasicOpAmpOutputStage.png

on the Device Models & Subcircuits Page of my website.
		
                                        ...Jim Thompson
-- 
| James E.Thompson                                 |    mens     |
| Analog Innovations                               |     et      |
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    |
| San Tan Valley, AZ 85142     Skype: skypeanalog  |             |
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  |
| E-mail Icon at http://www.analog-innovations.com |    1962     |
             
I love to cook with wine.     Sometimes I even put it in the food.
Jim Thompson wrote...
> > Basic OpAmp Output Stage Spice Model... Passes > load current to proper Voltage Rail... > No Voltage Bounds, No Current Limit, Yet ;-) > See... BasicOpAmpOutputStage.png > on the Device Models & Subcircuits Page of my website.
That's it, insures output currents are seen by the appropriate supply rail? If the output circuit comprised BJTs or FETs in a real-world fashion, this wouldn't be necessary. -- Thanks, - Win
On 9 Jan 2016 19:22:35 -0800, Winfield Hill <hill@rowland.harvard.edu>
wrote:

>Jim Thompson wrote... >> >> Basic OpAmp Output Stage Spice Model... Passes >> load current to proper Voltage Rail... >> No Voltage Bounds, No Current Limit, Yet ;-) >> See... BasicOpAmpOutputStage.png >> on the Device Models & Subcircuits Page of my website. > > That's it, insures output currents are seen > by the appropriate supply rail? If the output > circuit comprised BJTs or FETs in a real-world > fashion, this wouldn't be necessary.
...Jim Thompson -- | James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | San Tan Valley, AZ 85142 Skype: skypeanalog | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | I love to cook with wine. Sometimes I even put it in the food.
On 9 Jan 2016 19:22:35 -0800, Winfield Hill <hill@rowland.harvard.edu>
wrote:

>Jim Thompson wrote... >> >> Basic OpAmp Output Stage Spice Model... Passes >> load current to proper Voltage Rail... >> No Voltage Bounds, No Current Limit, Yet ;-) >> See... BasicOpAmpOutputStage.png >> on the Device Models & Subcircuits Page of my website. > > That's it, insures output currents are seen > by the appropriate supply rail? If the output > circuit comprised BJTs or FETs in a real-world > fashion, this wouldn't be necessary.
I'm trying to appropriately match real world devices... better BJT and MOS to come. ...Jim Thompson -- | James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | San Tan Valley, AZ 85142 Skype: skypeanalog | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | I love to cook with wine. Sometimes I even put it in the food.
On 9 Jan 2016 19:22:35 -0800, Winfield Hill <hill@rowland.harvard.edu>
wrote:

>Jim Thompson wrote... >> >> Basic OpAmp Output Stage Spice Model... Passes >> load current to proper Voltage Rail... >> No Voltage Bounds, No Current Limit, Yet ;-) >> See... BasicOpAmpOutputStage.png >> on the Device Models & Subcircuits Page of my website. > > That's it, insures output currents are seen > by the appropriate supply rail? If the output > circuit comprised BJTs or FETs in a real-world > fashion, this wouldn't be necessary.
I'm also seeking swing and current limits, independent for each rail. Plus, ultimately, I will match datasheet curves, irrespective of actual chip implementation. The ultimate object is to just insert information from a datasheet and spit out a model that matches every specification :-) I already have the "core" portion of the OpAmp done... put information from datasheet into a spreadsheet and it spits out coefficients for a behavioral expression (only ~12 lines long :-) that matches... DC Gain GBW Excess Phase Output Impedance Slew Rate + Slew Rate - Swing Limit + (and softness) Swing Limit - (and softness) All Noises versus frequency And can handle OpAmps with built-in compensation, or external. The most variability from device-to-device will be modeling the quiescent current behavior versus voltage and temperature... every designer does that differently. ...Jim Thompson -- | James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | San Tan Valley, AZ 85142 Skype: skypeanalog | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | I love to cook with wine. Sometimes I even put it in the food.
Jim Thompson wrote...
> > The ultimate object is to just insert information > from a datasheet and spit out a model that matches > every specification :-) > > I already have the "core" portion of the OpAmp > done... put information from datasheet into a > spreadsheet and it spits out coefficients for a > behavioral expression (only ~12 lines long :-) > that matches... > > DC Gain > GBW > Excess Phase > Output Impedance > Slew Rate + > Slew Rate - > Swing Limit + (and softness) > Swing Limit - (and softness) > All Noises versus frequency > > And can handle OpAmps with built-in compensation, or external.
That sounds super useful Jim, we'll be eager to see it when you post to your website.
> The most variability from device-to-device will > be modeling the quiescent current behavior versus > voltage and temperature... every designer does > that differently.
If it meets the rest of the criteria, w/o temp modeling, it'd still be super useful. a few comments: * Output Impedance - this is vs freq and load? * Slew Rate - this is vs input error voltage? -- Thanks, - Win
On 11 Jan 2016 05:28:16 -0800, Winfield Hill
<hill@rowland.harvard.edu> wrote:

>Jim Thompson wrote... >> >> The ultimate object is to just insert information >> from a datasheet and spit out a model that matches >> every specification :-) >> >> I already have the "core" portion of the OpAmp >> done... put information from datasheet into a >> spreadsheet and it spits out coefficients for a >> behavioral expression (only ~12 lines long :-) >> that matches... >> >> DC Gain >> GBW >> Excess Phase >> Output Impedance >> Slew Rate + >> Slew Rate - >> Swing Limit + (and softness) >> Swing Limit - (and softness) >> All Noises versus frequency >> >> And can handle OpAmps with built-in compensation, or external. > > That sounds super useful Jim, we'll be eager to > see it when you post to your website. > >> The most variability from device-to-device will >> be modeling the quiescent current behavior versus >> voltage and temperature... every designer does >> that differently. > > If it meets the rest of the criteria, w/o temp > modeling, it'd still be super useful. > > a few comments: > * Output Impedance - this is vs freq and load?
Only if that data is provided on the datasheet, OR, I have access to an actual device-level model... only one of my modeling clients has agreed to provide true internal information :-(
> * Slew Rate - this is vs input error voltage?
Yes. ...Jim Thompson -- | James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | San Tan Valley, AZ 85142 Skype: skypeanalog | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | I love to cook with wine. Sometimes I even put it in the food.