Test Op-Amp Power Rail Loading Mike DonnellyDesigner19 × Mike Donnelly Member for 10 years 4 months 1,529 designs 10 groups Title Description <p>Design example from the Webinar: “Creating New Components, Part 1: Datasheet Model Builder”. View the archive presentation here: </p><p>http://www.systemvision.com/webinars</p><p>This example shows the value of including the output current of an op-amp model, in the rail current load it applies to the external supply circuit. In this example, the requirement is that the sensor signal amplifier circuit continues to function for 100 milliseconds after the external power is disconnected (e.g. an airbag sensor circuit). If the designers are trying to select capacitors of sufficient size to supply the op-amp power for that duration, then accounting for all the op-amp load current draw it essential.</p><p>You can toggle the op-amp's "enable_supply_loading" to see the impact of this difference. With the "enable_supply_loading" unchecked, you can connect a static 5.5k Ohm "equivalent" op-amp load resistor to represent the "worst case" 1.8 mA quiescent current load of the op-amp, The output voltage of the op-amp will remain above the minimum 2 Vpeak-to-peak level for more than the required 100 milliseconds. But then if the "enable_supply_loading" is checked and the external resistor removed, the output voltage will decay long before the required operating time is reached.</p> About text formats Tags WebinarMDKEMETON-SEMINCV7101 Op-ampESH476M016AC3 Capacitor Select a tag from the list or create your own.Drag to re-order taxonomy terms. License - None - What's this? Design Titleby Mike Donnelly × Embed Design Copy Embed Code <iframe allowfullscreen="true" referrerpolicy="origin-when-cross-origin" frameborder="0" width="100%" height="720" scrolling="no" src="https://explore.partquest.com/embed-design/28566"></iframe> Embed Live Design Copy Embed Code <iframe allowfullscreen="true" referrerpolicy="origin-when-cross-origin" frameborder="0" width="100%" height="720" scrolling="no" src="https://explore.partquest.com/node/28566"></iframe> Share a Link Copy URL https://explore.partquest.com/node/28566