audio amplifier, Class-D audio amplifier, Texas Instruments

Class-D audio amplifier with integrated boost converter from Texas Instruments

News Release from: Texas Instruments
06/05/2008

Texas Instruments has introduced a monolithic, filter-free Class-D audio amplifier with an integrated boost converter for portable applications including wireless handsets, personal navigation devices, portable gaming and wireless speakers. Addressing the need for louder volume and higher output power from the speakers, the TPA2014D1 provides up to 1.5 W across an 8-Ohm load, ensuring that volume is maintained even when the battery discharges to its minimum voltage.

Conventional Class-D amplifiers for portable devices are designed to provide high output power, which is dependent on battery voltage. As the battery discharges, the maximum output power decreases, causing reduced volume and increased distortion. The TPA2014D1 provides a higher constant output power across the entire Li-Ion battery range, thus maintaining loud volume, even as the battery discharges. In addition, the TPA2014D1 has a high overall efficiency of 85 percent, which results in longer battery life and increased talk/playback time.

Additional features of the device enhance portable audio performance. The TPA2014D1 features a wide voltage supply range of 2.5 V to 5.5 V and a very high power supply rejection ratio (PSRR) of 91 dB, which simplify power supply design and enable a connection directly to the battery without any degradation of sound quality. The TPA2014D1 includes an integrated phase-locked loop (PLL), which synchronizes the Class-D amplifier and boost converter clocks in order to eliminate potential audible beat frequencies.