A dual 13A per output or single 26A output step-down regulator has been developed by Linear Technology Corporation that delivers up to 100A when four devices are current shared.
The LTM4620 DC/DC µModule (pronounced micromodule) is a complete DC/DC regulator system in a LGA package that includes inductors, power stages and all control circuits.
To optimise heat dissipation, a top side heat sink has been added to remove heat quickly and evenly. The device has 200LFM air flow, 12VIN to 1.0VOUT and at full load of 26A (or 13A per output), as a result, internal temperature rise only 60ºC above ambient.
The design has been enhanced with an external heat sink added to the top of the package and 200LFM air flow as a result the temperature rise is only 40ºC.
To demonstrate the capabilities the company has compiled a TechClip video at http://video.linear.com/p4634 for a performance demonstration.
The LTM4620 is designed to convert 5V to 12V inputs to high power, low voltage point-of-load system rails such as 2.5V to as low as 0.6V. An accurate reference and an internal remote sense amplifier guarantee +/-1.5% accurate output regulation over line, load and temperature.
Sensing the voltage at the load compensates for voltage drops caused by PCB trace impedance. Excellent heat dissipation, low temperature rise, scalable and high output power capability, small footprint and the low profile package of the LTM4620 enable system designers to lay out more densely populated boards. Applications include mezzanine boards such as ATCA and microTCA systems, point-of-load regulation for advanced processors, ASICs and recently introduced 28nm FPGAs as well as high-speed SERDES.
The device features fast short-circuit protection where a current foldback technique reduces IOUT to a minimum, preventing the µModule regulator from overheating while protecting the load as well as the upstream power supply.
Once the short-circuit condition is removed, it resumes operation (see TechClip video demonstration http://video.linear.com/p4634). The two outputs of the device operate at 180º out of phase to minimise output ripple (when outputs share current) and input ripple, resulting in the use of fewer and smaller capacitors. For a 100A design, four LTM4620 devices accurately current share and operate at 90º out of phase.