Why use load switches
Power management plays a more important role than ever in consumer and mobile electronics. At the system level, advanced load switches help to achieve simple, reliable and cost-effective solutions through control of sequencing, standby power consumption, input voltage dip/undershoot, OVP/OCP/OTP, and more where constrained form factors are required.

Fairchild’s rich load switch portfolio
Fairchild’s advanced integrated load switch family supports the latest generations of mobile industrial and consumer electronic devices. The IntelliMAX™ family integrates conventional MOSFETs with a complete suite of protection, control and fault monitoring features to facilitate power management and achieve high efficiency and reliability while minimizing board space. Applications include portable devices, set-top boxes, DVD players and consumer electronics, inventory management terminals and portable enterprise equipment, keyboards and keypads, GPS systems and wireless data systems, low voltage industrial and telecom and medical equipment, computing, and hard disk drives.

Fairchild’s slew rate-controlled load switches control the MOSFET turn on speed, help reduce the input voltage dip and avoid triggering UVLO. Over-current protection load switches allow users to set current limits to prevent overheating/overstressing if the downstream supply/load is shorted or goes over current with one of three protection options–constant current source, shut down, or auto restart. Over-voltage protection load switches will shut off the MOSFET if an over-voltage event at the output is sensed to prevent the downstream supply/load from experiencing abnormal voltage stress.  PowerMux switches are slew rate controlled MOSFETs which are able to toggle between dual inputs to source a downstream supply/load.

Design in a minute with Load Switch design tool
Fairchild offers more than 100 advanced load switches to meet various requirements for different applications. Manually selecting the right one and calculating component values can be tedious and time consuming, especially when it involves over-current protected switches where current setting is required plus selection from 3 protection options – current source/shutdown/retry at a fault condition. When shutdown feature is used, attention needs to be paid on the output capacitor value to avoid premature shutdown, since an over sized capacitor may trigger over current limit during startup. The Load Switch design tool takes all of these into consideration and provides the recommended component values for safe operation. Users can finish a design in one page, from entering basic input, output requirements, trying different available switches, generating BOM file, to buying/sampling a load switch. The available part table, schematic/component values, and BOM are updated dynamically after each spec change. It takes less than a minute to finish a complete design.

Load switch Design tool graphic

For more details and to start your design, please visit the Power Supply WebDesigner landing page and click the Load Switch tab.

This post is also available in: Chinese (Simplified)