TI boosts portable audio performance with 2.7-W constant output power Class-D Amplifier

The TPA2013D1 generates high output power from a low supply voltage without distorting the audio, and can also supply the power of external devices such as TI’s TPA2010D1, and other similar Class-D amplifiers. The device has a wide supply voltage operation of 1.8 volts (V) to 5.5 V to simplify power supply design and allow for direct connection to the battery. The new device provides a maximum output power of 2.7-W across a 4-Ohm load or 2.2-W across an 8-Ohm load in addition to providing an adjustable constant output power of up to 1.5-W in the entire Lithium-Ion battery range of 2.3 V to 4.8 V. This capability makes the audio output power insensitive to battery voltage fluctuations, thereby maintaining audio quality and volume as the battery discharges.

The innovative design of the TPA2013D1 eliminates the requirement for some external components enabling a total solution size of just 6.5mm x 6.5mm, which includes the amplifier, boost converter and external components. This represents a board area reduction of more than 50 percent compared to typical solutions. The combination of size, features and performance reduces overall system cost and allows for a sleeker, more differentiated end product.

“Consumers expect smaller, more power-efficient portable devices, including cellular phones, where future battery voltages may go as low as 2.3 V next year and even lower in 2009 and 2010,” said Gary Reichmuth, TI’s manager of audio and imaging products, high-performance analog. “Benefiting from TI’s in-depth systems expertise, products like the TPA2013D1 allow end equipment manufacturers to meet these consumer demands while increasing performance and functionality.”

Several key features of the TPA2013D1 help increase system audio quality. For example, all internal modules run off the same reference clock, silencing potential audible beat frequencies that could occur when using a separate discrete amplifier and boost converter. The synchronized clock and very high power supply rejection ratio (PSRR), 95 dB at 217 Hz, serve to further reduce noise in the system, avoiding “buzz” noises on amplifier outputs that can often be generated from RF power amplifiers in GSM phones, for instance.

The TPA2013D1 provides thermal and short circuit protection with an auto recovery option to ensure excellent reliability and robust operation. The device’s pinout has been optimized to reduce EMI, providing easy layout and meeting EMI requirements of the Federal Communications Commission (FCC).

The TPA2013D1 amplifier is optimized to work with other products from TI’s broad audio portfolio including portable audio converters such as the TLV320AIC3106, the TLV320DAC32 digital-to-analog converter and the Aureus™ platform of audio DSPs. TI provides the silicon, software, systems expertise and support for the entire audio signal chain, enabling customers to get to market quickly. For more information see the Audio Solutions Guide at http://ti.com/audio. In addition, see TI’s power management products for portable consumer applications at http://power.ti.com.