Hi all
I'm in the process of designing a bench top function generator (for the learning experience more than anything else) and I'm having some trouble understanding output current characteristics of op amps.
My design draws heavily from the example DIY function generator by Cezar Chirilla here on All About Circuits (however i plan on using the AD5932 chip and add a few more bells and whistles)
https://www.allaboutcircuits.com/pr...m-generator-analog-devices-ad9833-ATmega328p/
For some context
The circuit below takes the output from the AD9833 (i will use a AD5932) and first adjusts the amplitude of the signal (op amp in non-inverting config) and the second adjusts the offset (op amp as a summing amp). My confusion is around how much current can be drawn from the output of the second op-amp.
I haven't chosen an op-amp yet but lets say i use the LM318N, how can I determine the maximum output current if I have a very small load or short the output to ground?
I have seen that some op-amp data sheets have values for max output current (like the LM124N), but this one only seems to have supply current, is that output current?
Essentially I'm trying to work out if I need to put some circuitry into limiting the output current (only way I could think to do this is an AB amplifier because I want to be able to output negative and positive voltages) or if I can just heat sink the opamp enough that it will survive the output being shorted to ground while a sine wave with a +12V and -12V peaks is being outputted (or close to that).
In an ideal world, I would only attach the output to high impedance loads but will all do silly things sometimes and I want to protect my device from said silliness.
This is my first post on AAC so if i've broken any rules with this post please let me know and i will try and rectify them.
Thanks
I'm in the process of designing a bench top function generator (for the learning experience more than anything else) and I'm having some trouble understanding output current characteristics of op amps.
My design draws heavily from the example DIY function generator by Cezar Chirilla here on All About Circuits (however i plan on using the AD5932 chip and add a few more bells and whistles)
https://www.allaboutcircuits.com/pr...m-generator-analog-devices-ad9833-ATmega328p/
For some context
The circuit below takes the output from the AD9833 (i will use a AD5932) and first adjusts the amplitude of the signal (op amp in non-inverting config) and the second adjusts the offset (op amp as a summing amp). My confusion is around how much current can be drawn from the output of the second op-amp.
I haven't chosen an op-amp yet but lets say i use the LM318N, how can I determine the maximum output current if I have a very small load or short the output to ground?
I have seen that some op-amp data sheets have values for max output current (like the LM124N), but this one only seems to have supply current, is that output current?
Essentially I'm trying to work out if I need to put some circuitry into limiting the output current (only way I could think to do this is an AB amplifier because I want to be able to output negative and positive voltages) or if I can just heat sink the opamp enough that it will survive the output being shorted to ground while a sine wave with a +12V and -12V peaks is being outputted (or close to that).
In an ideal world, I would only attach the output to high impedance loads but will all do silly things sometimes and I want to protect my device from said silliness.
This is my first post on AAC so if i've broken any rules with this post please let me know and i will try and rectify them.
Thanks