The Conexant CX31993 (now often produced under the Synaptics umbrella following acquisitions) has become the gold standard for affordable, high-fidelity USB-C to 3.5mm audio adapters. While the public datasheet is restricted under NDA for manufacturers, extensive reverse engineering and community testing have allowed us to reconstruct a "functional datasheet" of its core specifications and electrical characteristics. 1. General Description The CX31993 is a low-power, high-performance audio codec with an integrated USB 2.0 full-speed controller. Unlike passive adapters, this active chip offloads all digital-to-analog conversion from the host smartphone or laptop, bypassing the device’s internal DAC and headphone jack.