T
Trevor Morton
- Jan 1, 1970
- 0
Well, I've seem to have managed to confound another group. So, please
excuse me for importing this thead.
Instead of continually changing op amps, I am seeking to devise a
single design suited to a wide range of applications. The desired
criteria are as follows.
4-12V power supply
Bandwidth _DC_ through 20KHz
DC coupled in and out
Unity to 20 gain, variable by trimpot
Low power DIP package
Drive resistive load of 20 to 200 ohms,
Output up to 2A, with Darlington follower
Swing as close to rail as is practical
At first, I thought such specs might be mutually exclusive in a fixed
design. However, if there are such limitations, they seem to be
receeding fast.
For example, there is the "new" OPA569, rated at 2A. It meets my
requirements except only operates up to 5.5V.
http://focus.ti.com/docs/prod/folders/print/opa569.html
Can someone explain, in theory or practice, why something like what I
am looking for cannot (apparently) be achieved with a "standard" op
amp and a couple of transistors? I am aware there are plenty such
devices dediciated strictly to audio, but they do not fit the bill on
several counts.
I can imagine this would be of lasting value to thoses who lack the
full range of engineering skills.
Thank you for any input.
Trevor Morton
excuse me for importing this thead.
Instead of continually changing op amps, I am seeking to devise a
single design suited to a wide range of applications. The desired
criteria are as follows.
4-12V power supply
Bandwidth _DC_ through 20KHz
DC coupled in and out
Unity to 20 gain, variable by trimpot
Low power DIP package
Drive resistive load of 20 to 200 ohms,
Output up to 2A, with Darlington follower
Swing as close to rail as is practical
At first, I thought such specs might be mutually exclusive in a fixed
design. However, if there are such limitations, they seem to be
receeding fast.
For example, there is the "new" OPA569, rated at 2A. It meets my
requirements except only operates up to 5.5V.
http://focus.ti.com/docs/prod/folders/print/opa569.html
Can someone explain, in theory or practice, why something like what I
am looking for cannot (apparently) be achieved with a "standard" op
amp and a couple of transistors? I am aware there are plenty such
devices dediciated strictly to audio, but they do not fit the bill on
several counts.
I can imagine this would be of lasting value to thoses who lack the
full range of engineering skills.
Thank you for any input.
Trevor Morton