Amplifiers

Devices

Throughout the course of this semester, the IPRO team performed a detailed analysis of two Class D amplifiers, and one Class AB amplifier.

Class AB: TPA1517DWPEVM

Class D: MAX9776EVKIT+, TPA3101D2EVM

Figure - comparison of class AB and class D amplifiers on efficiency vs. frequency

We can see from this graph that at 90% of the rated output power, the Class D amplifiers have an average efficiency of around 78%, while that of the class AB is approximately 50%.

Additionally, it can be seen from the following diagram that each of the class D amplifiers achieves much better efficiency in relation to output power when compared with that of the Class AB amplifier.

As this is the first semester of a multi-semester IPRO, the IPRO team feels that it is best to avoid jumping to any definitive conclusions. Any good researcher knows that discoveries and improvements only come after a long, concerted effort. Yet it must be acknowledged that the comparison between Class D and Class AB amplifiers has shown some very promising results. It has been observed that an improvement in efficiency of 25% - 30% can be obtained by using a Class D amplifier; a substantial improvement in any process. Such an improvement can have the effect of enabling your cell phone to operate on a single charge for days at a time, or your iPod to play music for you during an entire 20-hour train ride. This is a direct result of higher efficiency achieved by Class D amplifiers compared Class AB amplifiers. Therefore, we believe that further investigation into the use of and improvement in Class D amplifiers would be the correct course of action for next semester’s IPRO team.

*For detail analysis and test results for each amplifier, please follow the links on the right to each amplifier.