A direct-battery hookup, fully integrated stereo headphone module with 82 mW output power and 110 dB PSRR

A complete stereo ground-referenced headphone module that supports direct battery hookup is integrated on a 40 nm mobile baseband SoC. Several techniques were employed to guarantee the reliability of the module circuitry under high output swing and limited safe operating regions in this low-voltage technology. Additional techniques to reduce area and enable low-cost integration were also employed. The module delivers 3.24 Vpp to a 16Ω load (82 mW) and achieves 100 dB dynamic range (DR), 110 dB PSRR, and 84 dB THD+N with an area of 0.675 mm² on the SoC.