Electronic Device with Reverse Voltage Protection Circuitry for Multiple Control Lines

Abstract

A host electronic device may be coupled to an accessory electronic device. The host device and the accessory device may be connected via power supply lines and user data lines. If the host and accessory devices are improperly connected or if the accessory device is exposed to an incorrect voltage environment, the internal circuitry on the accessory device can be damaged. The accessory device may therefore include a reverse voltage protection circuit that can help prevent a large amount of current from inadvertently flowing into the accessory device. The protection circuit may include a low-side-enabled reverse current protection switch coupled between the external and internal ground terminals and also a single low-drop switch coupled to each of the user data lines. The low-drop switch will be activated whenever the voltage at the external ground terminal exceeds the voltage at the data line to help deactivate low-side-enabled reverse current protection switch.

Dependencies are inferred from the claim text.