10A micromodule regulator for 3.3V bus PoL applications

December 17, 2015 // By Graham Prophet
LTM4648 is a µModule (micromodule) regulator in a 9 x 15 x 4.92 mm BGA package, that accepts a 2.375V to 5.5V input (3.3V nominal bus) and delivers 10A µModule with full-current efficiency of 91%-95%, at up to 85°C ambient.

With an integrated 5V boost converter to drive the gates of its N-channel MOSFETs from low V IN supplies, the LTM4648 improves efficiency and simplifies system design by eliminating the need for 5V or 12V power rails and dependency on auxiliary regulators. Applications include point-of-load conversion from a 3.3V main power bus and battery-powered systems.

At full power (10A, full range of V OUT and V IN) is delivered when operating from 0°C to 85°C ambient temperature, while the LTM4648 requires no heat sink or airflow nor is its output current de-rated. Half-power occurs at high ambient temperature of 110°C (T JMAX=125°C). The µModule regulator operates at up to 91% efficiency (3.3V IN or 5V IN, 1.5V OUT at 10A). 95% efficiency is achieved when converting 3.3V IN to 2.5V OUT at 10A.

The LTM4648 regulates output voltages adjustable from 0.6V to 5V. Equipped with a differential remote sense amplifier to compensate for voltage droop due to circuit board trace impedance, the LTM4648 regulates a load voltage with ±1.5% accuracy over line, load and temperature (-40°C to 125°C).

The LTM4648 provides input and output clocks for multiphase operation among multiple devices to accurately current share for up to 40A load. Multiphase operation reduces input and output ripple as well as the number of input and output capacitors.

The LTM4648 is synchronisable to an external clock ranging in frequency from 400 kHz to 750 kHz. Burst Mode operation provides the highest conversion efficiency at light load and pulse-skipping operation lowers output voltage ripple. The LTM4648 permits output voltage tracking for sequencing multiple rails in a system. To protect the load, the LTM4648 features output overvoltage and overcurrent protection.

The LTM4648 E and I grades are guaranteed for internal operation from -40°C to 125°C. Pricing starts at $13.25 (1000).

Linear Technology; www.linear.com/product/LTM4648