We are developing a direct attach peripheral (no intermediate cable) that requires 20V@3.5A. How can we negotiate the higher power level (without an EMCA cable)?
If you are power sink role, and do not want to have a E-marker cable, the highest current shall be 3A. Since the power source shall detect EMCA capability before advertise SOURCE_CAP or by pass ALT MODE on USB signals. The voltage is not limitation.