A Power Switch provides an electrical connection from a voltage source or ground to a load. A power switch saves power across multiple voltage rails and protects subsystems from damage. It also provides enhanced component protection, inrush current protection, and minimizes printed-circuit board (PCB) size.
There are several power switch topologies with different features that address different applications. Load Switches establish the power switch foundation by providing safe and reliable distribution of power. Applications typically using load switches include power distribution, power sequencing, inrush current control, and reduced current leakage. Integrated Power MUX devices are similar to load switches and can seamlessly switch between different input power sources while providing protection features.
eFuses and Hot Swap controllers offer additional power path protection features such as current sense monitoring, current limiting, undervoltage and overvoltage protection, and thermal shutdown. This makes these devices ideal for hot-plug and transient events that would otherwise damage system components. These benefits help reduce system maintenance costs and maximize equipment uptime.
Ideal diode, ORing controllers provide protection against reverse-polarity conditions by monitoring an external FET, significantly reducing power loss, and blocking reverse current. Whenever a transient event occurs, the controller monitors and adjusts the external FET to prevent damage to upstream components.
Smart high-side switches provide additional diagnostic telemetry that monitors the output load current and detects short-circuit and open-load events. Smart high-side switches provide high current limits, allowing integration into applications that have large inrush current startup profiles.
Low-side switches connect the load to ground, instead of providing a connection between a power supply and the load. By including an integrated flyback diode, low-side switches help to eliminate inductive load transients by dissipating current in a circular loop. This allows them to drive inductive loads such as solenoids, relays, and motors.
This application note highlights the different topologies within the power switch portfolio, and provides suggestions in choosing the correct solution for a faster design time.