Regulator module provides power on the underside

Linear Technology introduces the LTM4631, a dual 10-A or single 20-A µModule (power module) step-down regulator in a 1.91-mm-high LGA package with a 16 x 16-mm footprint. The packaging is what makes this module significant and sets it apart from the competition. Why? Because the device provides a regulator, including the inductor, in one package, while the competition needs two chips. That means that the Linear product needs 400 mm² compared to 750 mm² for one competitor. At 1.91 mm, the height of the package is also very significant because it’s under 2.00 mm, which is a barrier to designs that aim to provide solutions for the underside of the PCB.

The micro-module can be placed on a PCB very close to the load, such as an FPGA, and can share one heat sink covering both of the low-profile packages. It frees space on the top side for components such as DDR-QDR memory and transceiver ICs. Examples of applications include plug-in and mezzanine cards in embedded systems, data storage systems, gateway controllers, and 40- to 100-Gbps networks.

For this module design, the company figured out how to make the inductor smaller, which materials to use, and even how to get the accuracy down to 1.5% error for the total dc output error over line, load, and temperature. The regulator operates from 4.5- to 15-V input supplies and regulates an output voltage from 0.6 to 1.8 V, and operates from –40°C to 125°C. Its two outputs operate 180° out-of-phase, each capable of delivering 10 A or 20 A when the outputs current share. Two devices can also current share, delivering up to 40 A.