Power management IC from ams helps reduce thermal stress on processors in phones and tablets

AUSTRIA: ams AG, a leading provider of high performance analog ICs and sensors, introduced the AS3721, a power management IC (PMIC) with an innovative remote-feedback circuit that helps reduce the thermal stress of applications processors in smartphones and tablets.

When paired with new AS3729 point-of-load regulators from ams, the highly-integrated AS3721 provides a complete power management system that offers a fast response to load transients for reliable processor performance, high efficiency, and flexible board layout.

The AS3721 and AS3729 are optimized for use with Tegra applications processors from Nvidia.

The AS3721 PMIC enables a compact remote feedback path from the processor to the IC’s integrated DC-DC controllers. Thanks to a patent-pending design innovation by ams, the feedback interface to the AS3721 only requires two wires (one control signal, one temperature signal) instead of the four or five wires typically required by other PMICs.

With fewer traces connecting the PMIC to the point-of-load power stages, the two devices can be placed far apart in the board layouts of space-constrained devices such as smartphones, tablets and notebooks. This dramatically reduces the size and intensity of the hotspot around the processor compared to conventional power architectures in which the processor and PMIC, both handling high currents simultaneously, must be located side-by-side.

The feedback loop carried over the AS3721’s two-wire interface also operates extremely fast, maintaining the processor it supports within its safe operating voltage even when supplying extremely fast-changing loads. Using an output capacitor of just 40µF and at an output voltage of 1.0V, the system’s voltage drop during a step up from 0.5A to 5A in burst mode is just 32mV (typical).