Slew rate controlled load switches

25th April 2007

Advanced Analogic Technologies Inc., Europe

ES Admin

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AnalogicTech’s slew rate controlled load switches have been used to replace discrete solutions in a variety of portable systems running off a 5V supply. By offering the same functionality for 12V operation, the AAT4285 allows designers - for the first time - to eliminate a discrete MOSFET and up to 11 external components in both higher-powered portable systems such as test equipment or camcorders as well as a wide range of non-portable industrial applications.

The AAT4285 is said to be the industry’s first integrated slew-rate controlled load switch capable of supporting 12V operation. By integrating level shift and slew rate control functionality into a single device, the AAT4285 allows designers to reduce power consumption and minimise parts count in a wide range of new 12V applications.

The AAT4285 is a P-channel MOSFET switch designed for high-side load switching applications. The device operates across a 3.0V to 13.2V input range. Functionally compatible with AnalogicTech’s AAT4250 and AAT4280 products, the AAT4285 offers a fast load switch turn-on time of 100µs. A fast shutdown load discharge capability allows the device to quickly turn off a load circuit when the switch is disabled.

The device also offers a very low RDS(ON) of 240mΩ typical at 12V to maximise load switch power handling capability. At 5V, RDS(ON) is 320mΩ typical. Quiescent current is 25µA typical.
The AAT4285 is the first 12V device manufactured in AnalogicTech’s ModularBCD process technology. Unlike aging linear-IC legacy fabs or generic digital CMOS foundries, the ModularBCD process represents the first of a new generation of analogue, power and mixed-signal IC technologies especially created for high-tech wafer fabrication and optimised for manufacture in ex-DRAM fabs.

The new process makes single-chip, mixed-signal and system ICs both more technically and economically feasible by monolithically integrating fully-isolated CMOS at 3V, 5V, and 12V with high-speed complementary bipolar transistors and robust 30V DMOS power devices without resorting to highly complex and expensive techniques such as epitaxy or high-temperature diffusion. As a result, devices manufactured in ModularBCD offer higher efficiency, smaller size, and higher levels of integration than devices fabricated in traditional processes, and can better manage power and extend battery life in a wide range of mobile consumer electronics products such as cell phones, portable media players, tablet and laptop computers and digital cameras.

Specified across the -40 to 85 degrees C temperature range, the AAT4285 is available in a Pb-free, 8-pin SC70JW package.