Circuit Breaker Protection Circuitry Built-in for Load Protection
Improved Cooling Effect Through Exposed Inductor on Top

Linear Technology has announced the launch of a new step-down µModule switching regulator (LTM4636-1) that can be expanded from 40A to 240A.

The product features built-in protection circuitry that trips a circuit breaker to protect the product itself, PCB, and loads such as high-current low-voltage processors, FPGAs, GPUs, and ASICs in the event of overvoltage or overheating error conditions.

The LTM4636-1 takes advantage of the BGA package structure in which the inductor is exposed on top and serves as a heat sink. This allows direct contact between air and inductor regardless of airflow direction, thereby further enhancing the cooling effect.



By stacking the inductor on top of the 16mm x 16mm BGA package, the LTM4636-1 can deliver 40W output with only a 40°C rise above ambient temperature (12VIN, 1VOUT, 40A, 200LFM). Maximum power of 40W is provided up to an ambient temperature of 83°C, while at 110°C ambient temperature it supports half the power level at 20W.

The LTM4636-1 operates at 92%, 90%, and 88% efficiency, delivering 15A, 30A, and 40A respectively to a 1V load (12VIN). Additionally, the µModule regulator is expandable—by paralleling four LTM4636-1 units, it can deliver 160W at 88% efficiency (12VIN, 1VOUT, 200LFM) with only a 40°C temperature increase.

The LTM4636-1 is designed to dissipate heat uniformly from the package bottom to the PCB through 144 BGA solder balls and through banks allocated to high-current GND, VIN, and VOUT nodes.

The LTM4636-1 µModule regulator combines excellent DC/DC conversion efficiency, enhanced thermal dissipation characteristics, and safety-enhancing protection circuitry, enabling system designers to utilize superior thermal performance along with voltage and thermal protection functions in a compact package.