Open Drainage

Open drainage is a method used in electronic circuits where a component's output is left "floating" unless it is actively driven low by an external device. Instead of directly connecting to ground or voltage, the output is left open, relying on external circuitry (like a pull-up resistor) to define the voltage level. This setup allows multiple devices to share a line without conflict, as they can only pull the line low when needed. Open drainage is commonly used for implementing wired-AND logic functions and simplifying communication between devices, particularly in scenarios like I²C buses.