Highly integrated, slew rate controlled load switch supports 1.5V inputs for reduced power consumption

As portable system processors and chipsets continue to push operating voltages lower with each new generation, they need load switches capable of supporting lower voltages. By integrating slew rate control, support for 1.5V input, and an extremely low quiescent current, AnalogicTech’s AAT4280A family of integrated load switches gives designers the control they need to drive down power consumption and build a more competitive portable product.

Designed to control internal loads by slowly ramping up output voltage at a desired rate, the intelligent switches prevent current spikes and sags in input supply rails in a wide variety of portable devices including cellular handsets, PDAs, and digital cameras.

Taking advantage of AnalogicTech’s proprietary process technology and innovative circuit design, the AAT4280A combines an extremely low resistance P-channel MOSFET with logic level input and level shifting features to eliminate multiple components on a PCB. The device’s resistance drain to source (RDS or ‘ON’ resistance) is a very low 80mohms at 5V input supply typical.

The AAT4280A is available in three distinct versions. With a moderate turn-on slew rate, the AAT4280A-1 reduces in-rush current when the MOSFET is turned on. The second version, the AAT4280A-2, serves as a high-speed switch with a typical turn-on time of 500ns. For simplicity, this device does not offer any turn-on slew rate control or special output discharge features. The AAT4280A-3 adds a minimized slew rate limited turn-on function and a shutdown output discharge circuit to rapidly turn off a load when the switch is disabled.

All three versions of the AAT4280A support operation over a wide 1.5V to 5.5V input range. Quiescent current is an extremely low 25nA. Input logic levels are TTL and CMOS compatible.

AnalogicTech’s AAT4280A is available in a tiny (2.0 x 2.2mm) 8-pin SC70JW package and is specified over the –40 to +85 degree C temperature range.