25A μModule Regulator Supports N+1 Redundancy to Ensure Power Supply Availability in Fault Conditions

Linear Technology Corporation, a member of Analog Devices, Inc., introduced the 25A step-down μModule® (power module) LTM4645, which can be used in multiple independent devices (N). The current is divided equally between at least one LTM4645 for backup (+1) to ensure power availability when a device in the N+1 configuration detects a fault and must be disconnected. For example, a 75A, 1V load such as an ASIC requires 3 LTM4645s to provide a total of 75A (= 3 x 25A) current. To provide system resiliency, an additional LTM4645 was added as a 3+1 form backup, resulting in four LTM4645s sharing the current to provide 75A in the event of an LTM4645 failure. Applications that can benefit from the N+1 redundancy features of the LTM4645 include data centers, aerospace, banking transactions, and cloud systems, where improving system security and integrity is a top priority.

The LTM4645 operates from a 4.7V to 15V input supply and the output voltage can be adjusted from 0.6V to 1.8V. Synchronous buck operation provides 25A (at 1V) output from 12VIN with 86% efficiency, resulting in 3.5W power dissipation and 41°C temperature rise (no airflow, no heatsink). The device is available in a 9mm x 15mm x 3.51mm BGA package and includes an inductor, MOSFET, and DC/DC regulator IC. A differential far-end sampling amplifier was used to compensate for the voltage drop caused by the PCB trace resistance. The electrical parameters were tested over the temperature range of –40°C to 125°C and the total DC accuracy of the output voltage was guaranteed to be ±1.2%. Propagation delay (from the time the faulty device was turned off) is less than 200ns.

The LTM4645 operates from the –40°C to 125°C temperature range. Up to 6 devices can share 150A load current. With a 12V input to 1V output and a 25A load, the power consumption is only 3.5W. For 12V input, 1V output conversion, full power is provided at up to 75°C (0LFM without heat sink) and load current is derated to 20A at 85°C.

Relevant LTM46 series products

Author：Brittany Antonia （The author of article owns the copyright.）