Stacked-package, inductor-on-module structure enables 40A DC/DC in 200 mm²

November 28, 2016 // By Graham Prophet
LTM4636 is a 40A step-down µModule (“micromodule”) switching regulator with 3D construction for quicker heat dissipation and cooler operation in a small package. It contains a switching controller plus power MOSFETs, inductor and components supporting internal and external compensation.

By stacking its inductor on top of a 16 x 16mm BGA package, the LTM4636 both directly dissipates heat generated within the inductor, and uses the inductor as a heatsink to conduct heat out from semiconductor devices within the package. This permits airflow from any direction to cool the device. The LTM4636 delivers 40W at 88% efficiency (12V IN, 1V OUT, 40A, 200 LFM) with only 40°C rise over ambient temperature. Full-power 40W is delivered up to 83°C ambient and half-power 20W is supported at 110°C ambient. The device operates from a 4.7V to 15V input supply and regulates an output from 0.6V to 3.3V set by an external resistor.

Current mode operation allows precise current sharing of up to six LTM4636 regulators to obtain a 240A output. The LTM4636 is offered in a thermally enhanced 16 × 16 × 7.07 mm BGA package.


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