AN: Basic OpAmp Output Stage Spice Model Posted to my Website
Jan 09, 2016 6 Replies
J
Jim Thompson
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
formatting link
| 1962 | I love to cook with wine. Sometimes I even put it in the food.
Didn't find your answer? Ask the community — no account required.
W
Winfield Hill
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
J
Jim Thompson
...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.
J
Jim Thompson
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.
J
Jim Thompson
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.
W
Winfield Hill
That sounds super useful Jim, we'll be eager to see it when you post to your website.
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
J
Jim Thompson
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 :-(
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.
Join the Discussion
Have something to add? Share your thoughts — no account required.
Didn't find your answer?
Ask the community — no account required
Report Content
You are reporting this content to the moderators. They will look at it
ASAP.