Texas Instruments introduced an audio operational amplifier (op amp) that sets the latest standard in audio performance. The OPA1622’s small size, low-power consumption and low distortion can deliver high-fidelity audio in portable devices such as headphone amplifiers, smartphones, tablets and USB audio digital-to-analog converters (DACs).
The OPA1622 is the newest addition to the company’s Burr-Brown Audio line and is the next generation of the widely adopted OPA1612. The new device delivers high output power of up to 150mW and extremely low distortion of -135 dB at 10mW, enabling the highest performance for professional audio equipment.
Headphone amplifier designers can take advantage of the device’s low total harmonic distortion (THD) of -135 dB at 10-mW output power into a 32-Ω load – 12 times better than the nearest competitor. It also delivers maximum output power of up to 150mW before clipping while maintaining the lowest THD and noise (THD+N), providing a clean signal path for professional audio applications.
Optimised for high-fidelity portable audio devices, the device consumes low quiescent current of 2.6-mA per channel and delivers high linear output current of 80 mARMS in a small, 3-mm-by-3-mm dual flat no-lead (DFN) package. Additionally, the increased power-supply rejection ratio (PSRR) of -97/-123 dB at 20 kHz enables low distortion from switching power supplies with no low-dropout regulator (LDO), saving board space without compromising audio performance.
The device’s unique pinout simplifies design by improving printed circuit board (PCB) layout and enabling exceptional distortion performance at high output power. The OPA1622’s ground-referenced enable pin is directly controllable from the low-power processor’s general-purpose input/output (GPIO) pins without level-shifting circuits. Further, the op-amp has a unique enable-circuitry design which limits output transients when the OPA1622 is transitioning into or out of shutdown mode, thereby eliminating audible clicks and pops.
Designers can leverage the toole and support available for the device to head-start their designs. A TINA-TI SPICE macromodel is available for the OPA1622 to help designers verify board-level signal-integrity requirements. A precision reference design for voltage-output audio DACs will be available in 1Q16 to speed time to market for OPA1622-based headphone amplifier designs.