The AAT4616 SmartSwitch is a current-limit P-channel MOSFET power switch designed for high-side load switching applications. This switch operates with inputs ranging from 2.4 V to 5.5 V, making it ideal for both 3 V and 5 V systems. An integrated, highly accurate current-limit circuit protects the input supply against large currents, which may cause the supply to fall out of regulation. Reverse current blocking is provided to protect the load switch from reverse current flows while the device is in shutdown. The AAT4616 is also protected from thermal overload, which limits power dissipation and junction temperature. Current-limit threshold is programmed with a resistor from SET to ground, and is adjusted for load levels up to 1.6 A. The ultrafast current limit response to a sudden short circuit is 2 s, which reduces the requirements of local supply bypassing. An open-drain FAULT flag signals an over-current or over-temperature condition. To prevent false reporting, a 4 ms time interval is used at startup (charging a capacitive load), where fault conditions are not monitored and reported. Quiescent current is a low 10 A and the supply current decreases to less than 1 A in shutdown mode. The AAT4616 is offered in small Pb-free, 5-pin SOT23-5 and TDFN22-8 packages, and is specified for operation over the –40°C to +85°C ambient temperature range. A typical application circuit is shown in Figure 1. The pin configuration is shown in Figure 2. Signal pin assignments and functional pin descriptions are provided in Table 1.