Regulator protects load by tripping power source

The LTM4636-1 from Linear Technology is a 40A to 240A scalable step down µModule switching regulator. The part incorporates protection circuitry that trips a circuit breaker in the event of overvoltage or over temperature fault conditions to protect itself, the PCB and loads – including high current low voltage processors, FPGAs, GPUs and ASICs.

An output crowbar function clamps the output to protect the load during an overvoltage condition. The LTM4636-1 benefits from a 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.

The LTM4636-1 operates from 4.7 to 15V input supply and regulates an output voltage from 0.6 to 3.3V. Total DC output voltage accuracy is ±1.3% from –40 to 125°C.

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

The regulator is scalable from two to six devices and operates at 92%, 90% and 88% efficiency, delivering 15A, 30A and 40A, respectively, to a 1V load from 12VIN.

In addition to dissipating heat from the top, the LTM4636-1 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.

Author
Peggy Lee