Load Switches Simplify Multiple Voltage Designs

Three new level-shifted load switches have been developed, each allowing a low-voltage µC to control loads on a range of different voltage rails. Two of the Little Foot TSOP-6 devices are higher-performance versions of competing parts, with the third device, the Si3865DV, representing the first 1.8V load switch. Designed to accommodate multiple rail voltages in cellular telephones and portable computers, the three devices have on-resistances as low as 80 milliohms when switching 4.5V loads. The integrated n-channel level-shift circuits save space by eliminating the need for an external MOSFET to give a true ground referenced low voltage logic input. Only a resistor is needed to form a complete solution. The n-channel component of each device can be driven by logic signals as low as 1.5V.