40A scalable µModule regulator protects by tripping power source

February 09, 2017 // By Graham Prophet
LTM4636-1 is a 40A to 240A scalable step-down µModule (“micromodule”) switching regulator. The part incorporates protection circuitry that trips a circuit breaker in the event of overvoltage or overtemperature fault conditions to protect itself, the PCB it resides on, and loads such as high-current low-voltage processors, FPGAs, GPUs and ASICs.

An output crowbar function quickly clamps the output to protect the load during an overvoltage condition. The LTM4636-1 employs an innovative BGA package construction in which the inductor is exposed on top and is used as a heat sink, permitting direct contact with airflow from any direction for more effective cooling.


By stacking the inductor on top of a 16 x 16 mm BGA package, the LTM4636-1 can deliver 40W with 40°C rise over the ambient temperature (12 VIN, 1 VOUT, 40A, 200 LFM). Full-power 40W is delivered up to 83°C ambient and half-power 20W is supported at 110°C ambient.


The LTM4636-1 operates at 92%, 90% and 88% efficiency, delivering 15A, 30A and 40A, respectively, to a 1V load from 12 VIN. The µModule regulator is scalable, so four LTM4636-1s in parallel can deliver 160W with only 40°C rise and 88% efficiency (12 VIN, 1 VOUT, 200 LFM).


Total device height is 7.07mm with a 16 x 16 mm BGA footprint. In addition to dissipating heat from the top, the package is designed to uniformly disperse heat from the bottom of the package to the PCB with 144 BGA solder balls, with banks of solder balls assigned as GND, VIN and VOUT where high current flows. The µModule regulator provides high DC/DC conversion efficiency, enhanced heat dispersion and safety circuitry, ensuring enhanced thermal performance, as well as voltage and thermal protection in a small package. The LTM4636-1 operates from 4.7V to 15V input supply and regulates an output voltage from 0.6V to 3.3V. Total DC output voltage accuracy is ±1.3% from –40°C to 125°C and pricing is $44.11 (1,000).


Linear Technology; www.linear.com/product/LTM4636-1