A MOSFET emulating a diode but with 10x lower voltage drop and power loss is called an ideal diode. Like a regular diode-OR, an ideal diode-OR selects the highest voltage input supply to power the output. This is suitable for systems with redundant supplies having similar nominal voltages. As mentioned, voltage level is not the main criteria for powering the system in battery-powered applications. The wall adapter powers the system as long as it is available, i.e., it has higher priority than the battery. This can be implemented with an ideal diode-OR circuit as shown on this slide. The LTC4416 dual ideal diode controller monitors the high priority source, a 12V wall adapter, with the R2A-R2C resistive divider and blocks the lower priority supply through the /E2 input as long as the wall adapter input voltage is above the 9V threshold. This implementation works for a 2-input system but gets complicated with 3-inputs. Designing such systems with diode-OR controllers or comparators with discrete logic requires careful planning and makes the design difficult to change at the last minute. A prioritizer provides a better solution than a diode-OR, especially when the preferred power source is not the highest voltage because the prioritizer does not necessarily draw current from the highest voltage supply.