µModule regulator ensures power availability under fault conditions

Linear Technology, which was recently acquired by Analog Devices, has unveiled the LTM4645, a 25A step-down µModule (power module) regulator that is able to current share multiple independent devices (N) where at least one LTM4645 is used as backup (+1) to ensure power availability if one device in this N+1 arrangement detects a fault and has to be disconnected.

According to the company applications benefiting from the LTM4645’s N+1 redundancy feature will include: data centres, aerospace, banking transactions and cloud-based systems where improved system safety and integrity are seen as priorities.

The LTM4645 operates from 4.7V to 15V input supply and regulates an output voltage adjustable from 0.6V to 1.8V. Synchronous step-down operation delivers 25A at 1V from 12VIN with 86% efficiency, 3.5W power loss and 41°C rise (no airflow, no heat sink).

The device is available in a 9mm x 15mm x 3.51mm BGA package and includes the inductor, MOSFETs and DC/DC regulator IC. With a differential remote sense amplifier to compensate for voltage droop caused by PCB trace resistance and tested electrical parameters from –40°C to 125°C, the output voltage total DC accuracy is guaranteed at ±1.2%.

The LTM4645 has a number of safety functions such as output overvoltage protection, output overcurrent protection, and an onboard temperature monitoring diode. The propagation delay from time of failure device turn-off is less than 200ns.

Rated for operation from –40°C to 125°C, up to 6 devices can current share for 150A of load current. Power loss is 3.5W for 12V input to 1V output at 25A load. For 12V input, 1V output conversion, full power is delivered up to 75°C (0LFM, no heat sink) and at 85°C derating of load current is 20A.

Neil Tyler