Scalable regulator trips upstream power source to protect
Protection circuitry is incorporated in the LTM4636-1 40 to 240A, scalable, step-down iModule switching regulator.
The circuitry trips a circuit breaker in the event of over-voltage or over-temperature fault conditions. An output crowbar function quickly clamps the output to protect the load during an over-voltage condition. The LTM4636-1 has 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 for more effective cooling, says Linear Technology. It is also 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.
By stacking the inductor on top of a 16 x 16mm BGA package, the LTM4636-1 can deliver 40W with only 40 degree C rise over the ambient temperature (12VIN, 1VOUT, 40A, 200LFM). Full-power 40W is delivered up to 83 degree C ambient and half-power 20W is supported at 110 degree C ambient. Total device height is 7.07mm.
The regulator operates at 92, 90 and 88 per cent efficiency, delivering 15, 30 and 40A, respectively, to a 1V load from 12VIN. The regulator is scalable, so four in parallel can deliver 160W with only 40 degree C rise and 88 per cent efficiency (12VIN, 1VOUT, 200LFM).
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 per cent from –40 to +125 degree C.