This part (80V!!) looks like a good candidate for a higher power audio amplifier. How many OPA593 parts do you think can be successfully paralleled in a composite design (driven by a single high-performance opamp)? And what would be the limiting factor(s) when paralleling multiple 593 parts?
Hi Josh,
is there an app note for paralleling either the BUF634 or the LME49600?
I did not see that we have any collateral in paralleling the buffer circuit, but there are some E2E inquiries and replies in the topics. We are certainly able to simulate the application, if you want to parallel these buffers at the output. We will need to know what is driving load for the application.
https://e2e.ti.com/support/audio-group/audio/f/audio-forum/745822/lme49600-paralleling-devices
From the previous E2E replies, you will see that you can not simply parallel multiple buffers at the output. The output stage and design approach would be very similar to parallel OPA593s to increase the output current. A small value resistor has to be inserted at the output of each buffer in order to avoid the "fight" among multiple parallel output stages.
If you are taking one of our precision grade audio op amp and add AB class power buffer stage at the output, you should get similar results vs. paralleling multiple stages of buffer stages. LME49600 buffer is lower cost than BUF634, and it will not be cost effective if the application requires couple for driving the higher current application. If you are able to use matching complementary BJT transistors at the output stage (e.g. AB driving configuration), you should be able to build a comparable and higher current driving stage for the audio application.
The Figure 2 above is taken fromLME49600 simplified buffer circuit. For the audio application, you will need to use the matching NPN/PNP to build AB class stage for audio application. You may also design other audio output stages and use matching Darlington and/or Sziklai output transistor configurations to boost the current at the stage.
Here is another audio output driving configuration, where the audio load is driving differentially with push pull output stage. The audio load is "floating" in the driving configuration.
If you have additional questions, please let us know.
Best,
Raymond
