High Linear Output Current, Maximizing Performance Limits with Low Power

TI announced the launch of new audio operational amplifier products that set new standards in audio performance.

The new OPA1622 is a newly added product to TI's Burr-Brown™ audio line and represents the next-generation successor to the currently widely used OPA1612.
The OPA1622 delivers high output reaching up to 150mW and improves performance with extremely low distortion of -135dB at 10mW, making it suitable for professional audio equipment.

Additionally, its compact size, low power consumption, and low distortion characteristics enable High Fidelity (Hi-Fi) audio in portable devices such as headphone amplifiers, smartphones and tablets, and USB audio digital-to-analog converters (DACs). TI plans to demonstrate the OPA1622 at CES 2016.

One of the product's advantages is that headphone amplifier developers can favorably leverage the low THD (total harmonic distortion) of -135dB at 10mW output with a 32Ω load. This represents more than 12 times superior performance compared to the closest competing product. Additionally, it provides output power reaching up to 150mW before clipping and maintains very low THD and noise (THD+N), thereby providing a clean signal path for professional audio applications.

In a compact 3mm x 3mm DFN (dual flat no-lead) package, it consumes a low quiescent current of 2.6mA per channel and provides high linear output current of 80mARMS. Additionally, the excellent PSRR (power supply rejection ratio) of -97/-123dB at 20kHz reduces distortion from switching power supplies and eliminates the need for an LDO (low-dropout regulator), thereby saving board space without compromising audio performance.

The OPA1622's ground reference enable pin can be controlled directly from a general-purpose input/output (GPIO) pin of a low-power processor, eliminating the need for level-shifting circuitry. Additionally, the innovative pinout improves PCB (printed circuit board) layout and provides excellent distortion performance at high output power.

Audible "click and pops" elimination: Using a proprietary enable circuit, the OPA1622 limits output transients when transitioning to shutdown mode or exiting from shutdown mode.

Developers can verify board-level signal integrity using the TINA-TI™ SPICE macro model for the OPA1622. Additionally, TI Designs will provide a precision reference design for voltage output audio DACs in Q1 2016, thereby reducing future OPA1622-based headphone amplifier design time.

Engineers can search for solutions, obtain assistance from peer engineers and TI experts, share knowledge, and resolve problems in the Precision Amplifiers forum of the TI E2E™ community.

Furthermore, engineers can acquire more in-depth audio expertise through TI's on-demand training series TI Precision Labs – Operational Amplifiers, which covers diverse topics including low distortion design and noise. The video demonstrates how developers achieve overall system performance objectives using actual circuits.

The OPA1622 is available in a 3mm x 3mm DFN package, with pricing at $2.90 per unit based on quantities of 1,000 units.

System developers can use TI's PCM1794A Burr-Brown Audio stereo digital-to-analog converter (DAC) together with the OPA1622 to build high-performance audio signal paths. Additionally, TI's TPS65133 and TPS65132 split-rail converters can be used together as power supply solutions suitable for portable audio applications.