We all like to take our music with us on MP3 players. And since the invention of the boom box, many of us like to share our music as well. Shrinking the size of the boom box without sacrificing performance has been a constant innovation area for decades. A portable Bluetooth® speaker is one such step on this innovation pathway.
With a focus on smaller size and longer battery runtime – without sacrificing loudness, of course – power management is increasingly critical. Efficiently taking the single-cell lithium battery’s energy and driving 20-30W speakers is a key design challenge. Due to the 10A switch currents required at this power level, a controller-based solution with external MOSFETs was previously all that was available. Now, the TPS61088 integrates both MOSFETs (providing synchronous rectification for higher efficiency) and delivers the required output power. Figure 1 shows that it delivers up to 95% efficiency at full power.
Figure 1: The TPS61088 provides efficiency well above 90%, even at full output power
Another key feature of the TPS61088 is its scalability; you can adjust the level of current-limit protection with just a resistor. So the same design can drive different speakers of different power levels, while still being protected from short circuits and other faults at reasonable power levels for a given speaker. This flexibility allows design reuse and faster time to market for similar speakers at different power levels.
Which do you prefer: keeping your music to yourself with a personal MP3 player or sharing it with a Bluetooth® speaker?