We have been using class AB audio amplifiers for dc-coupled analog servo motor drive for years. Now as we push for much smaller packaging, heat dissipation is a major issue. I have been searching for a 15-20W, BTL, class D solution with ANALOG control input. Can anyone point me to a device/family that might work for this type of application?
Please take a look at the TPA3112D1. Let me know if this doesn't make sense for you and we can go from there.
Motor Drive Application Manager
Thanks. I had tried working my way through the selection guide and ended up with the TPA series which seemed like it would be worth digging into a bit more. I was discouraged though by some of the comments in the audio forum about dc-coupling being a bad idea, and I was not sure how it would affect the bootstrapping, etc.
I have a little concern about the speaker guard technology triggering during normal operation, but since this a servo application, the input signal is likely to be small for long (slow) moves taking longer than the 420ms, and fast moves will involve a polarity change for accel/decel, so I guess that might just work out fine.
Any tips on biasing the input signal to match the 3V expected on the inputs?
I'll try and ask this another way. How do I correctly dc couple an analog signal that will typically be biased at something like VCC/2. Is there an app note available?
I am really sorry for leading you down the "garden path" here on the analog input audio amplifiers. The input structure will not support a DC coupled input.
I am afraid that there are no parts in the line-up that do.
All content and materials on this site are provided "as is". TI and its respective suppliers and providers of content make no representations about the suitability of these materials for any purpose and disclaim all warranties and conditions with regard to these materials, including but not limited to all implied warranties and conditions of merchantability, fitness for a particular purpose, title and non-infringement of any third party intellectual property right. TI and its respective suppliers and providers of content make no representations about the suitability of these materials for any purpose and disclaim all warranties and conditions with respect to these materials. No license, either express or implied, by estoppel or otherwise, is granted by TI. Use of the information on this site may require a license from a third party, or a license from TI.
TI is a global semiconductor design and manufacturing company. Innovate with 100,000+ analog ICs andembedded processors, along with software, tools and the industry’s largest sales/support staff.