Wearable and handheld electronic design comes with an inherent tradeoff between battery life, feature richness, and size. To fit the most features in a small device, you want the smallest, most efficient power management scheme. For simple battery-powered devices, all you often need is a diode ORing. A diode ORing powers the device from the battery when unplugged and switches to the charging cable when plugged in. This simple scheme uses two diodes to select the option with the higher voltage. However, diodes have an inherent tradeoff between forward voltage, leakage, size and cost, where you generally get to pick two.
Diode ORing controllers improve this scheme by using MOSFETs to mimic diodes to improve efficiency, but they aren’t the smallest or lowest cost option. The MAX40200 ideal diode, however, solves this tradeoff and gives you the best of all four parameters, allowing a simple design with the smallest size, high efficiency, low leakage, and low cost.
The short video below compares the four common ways to accomplish diode ORing, and there is a clear winner. Watch and learn today!