Texas Instruments’ TPA3125D2N – Audio Amplifier Design

Audio amplifier design is an interesting and annoying task – while some made a fortune writing books on the topic, in many cases, any amplifier is good enough. Normally, parts such as the PAM8302 get used. In practice, one often needs more power – in this case, Texas Instruments TPA3125D2N is the part to call on.

While the part comes in an easy to handle DIP package, do not let the packaging fool you. Texas Instruments uses a modern class D amplifier, and can supply either 10 or 20 watts into an eight ohm speakers when supplied with 24 V of direct current.

However, due to the high efficiency of the part, no heatsink is needed when approaching the extremely high values. From a technical point of view, the TPA3125D2N is relatively simple. Driving a speaker, in principle, is done with the following application example.

Driving a speaker with the TPA3125D2N is pretty simple

Sadly, working with low input voltages is not a strength of the part. The lowest supply voltage Texas Instruments specifies in the data sheet is 10V – the figure shows how the output power varies across the various input voltages.

Output power depends on input voltage

Another interesting aspect involves circuitry intended to eliminate the popping sound found when connecting or disconnecting power or speakers. This is highly valuable, as it reduces potential risk of damage to the audio system.

Finally, let’s also recommend a look at the data sheet found by Clicking Here – it contains interesting additional information on power supply problems and similar issues encountered when dealing with class D amplifyers.

Recent Articles
STSPIN32F0 – Series
Extremely integrated STM32-based system-in-package solution for driving three-phase BLDC motors We would like to introduce you to ST’s growing portfolio of STSPIN32F0 devices. Embedding a 32-bit ARM... Read Article
Enter for your chance to win a Digilent Dev Board worth over $500
To celebrate our 10 Year Anniversary this month and to thank everyone for their support over the last decade, we’ve partnered with Digilent to give away 2x Digilent development boards... Read Article
Efficient High-Power Gallium Nitride FETs from Nexperia
Whether designing a motor drive/controller for the next generation of battery-electric vehicles, or a power supply for the latest 5G telecommunication networks, Nexperia’s GaN FETs will be key... Read Article
Debug your embedded systems from the home office
Use USB Logic Analyzer and Pattern Generator to debug, visualize, and simulate signals in digital systems The quarantines are forcing an increasing number of engineers and... Read Article
Learn more about Optocoupler Design for EMI Immunity by Broadcom & EBV
Join the IEEE Webinar on 26th May, 4pm CET – Optocoupler Design for EMI Immunity Also available on demand This webinar takes a close look into... Read Article
6 use cases for adaptable technology and its impact on automotive trends
Overcome technological complexity in automotive design with Xilinx and Avnet Silica The automotive industry is a highly competitive space. In the blink of an eye, a... Read Article