This envelope-tracking power reference design maintains helps extend battery life in a portable audio applications, such as Bluetooth® or Wi-Fi speakers. The low-power step-down converter in the design features envelope-tracking capability to an audio power amplifier, maintaining high efficiency across the output voltage range. By adding an audio envelope signal to the FB pin of TI’s TPS61178 device, the output voltage can change in accordance with the envelope of the audio signal thus dynamically adapting the TPA3128D2 power amplifier’s supply and optimizing its power consumption.
Features
- 5.4V to 8.4V input voltage range
- 2X20W into a 8-Ω load at Vin=7.2V
- Programmable power limit
- Isolate the input battery from the output side when shut down
- High efficiency and small solution size