Hi-fi headphone driver allows sustained dynamic range of more than 120 dB

Texas Instruments has introduced the TPA6120A2, a high-fidelity headphone driver that completes an entire audio signal chain for super-audio compact disc (SACD) and DVD audio players and other systems with similar demanding requirements. When matched with the OPA4134 audio operational amplifier (op amp) and the PCM1792 or DSD1792 digital-to-analog converter (DAC) from TI's Burr-Brown product line, the entire audio chipset maintains a dynamic range greater than 120 dB.

The TPA6120A2 is based on current-feedback architecture. Three key advantages make current-feedback amplifiers excellent low distortion audio power amplifiers. First, a 1300 V/us slew rate prevents odd order distortion anomalies. Together with the slew rate, the high current-on-demand output enables the amplifier to respond quickly and linearly, avoiding any output distortion and unwanted noise. Finally, the gain-independent frequency response maintains the full bandwidth of the amplifier at any gain setting, which keeps excess loop gain from decreasing and causing harmonic distortion.

Superior sound quality from the OPA4134 is derived from its FET input stage and high drive output stage. The FET inputs respond quickly and the output signal can swing to nearly 1 V from the supply rails when driving impedances greater than 2 k ohms. This delivers an ultra-low 0.00008 percent total harmonic distortion (THD) and 8 nV/√Hz noise floor.

The PCM1792 and DSD1792 D/A converters employ TI's advanced-segment sigma-delta architecture, enabling dynamic range performance of up to 132 dB, with improved tolerance to clock jitter. Balanced current outputs provide increased immunity to noise and allow the user to optimize the analog performance with the output filters. Both the PCM1792 and DSD1792 accept 24-bit PCM and 1-bit DSD audio data formats, and features such as digital attenuation, de-emphasis and soft mute can be controlled with SPI or I2C interfaces.

In addition to offering the complete signal chain, TI offers the AureusTM family of audio digital signal processors (DSP) to perform the audio processing functions in high-fidelity systems. For more information on TI's complete offering of products focused on audio systems, please see the Audio Solutions Guide available at

The TPA6120A2, OPA4134, PCM1792 and DSD1792 are available now from Texas Instruments and its authorized distributors. The TPA6120A2 comes in a standard PowerPADTM surface mount 20-pin small outline package (SOIC). The OPA4134 is available in a standard 14-pin dual inline package (DIP) and a standard 14-pin small outline package (SOIC). The PCM1792 and DSD1792 are available in a standard surface mount 28-pin small shrink outline package (SSOP).

Suggested resale pricing in quantities of 1,000 start at $1.90 for the TPA6120A2, $1.75 for the OPA4134 and $13.65 for the PCM1792 or DSD1792.

The data sheet for the TPA6120A2 is available here: TPA6120A2 data sheet.

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