55V, 300W Source/Sink Hybrid Step-Down Non-Isolated μModule Bus Converter

The LTM4654 is a complete 300W output source/sink switching mode hybrid-topology step-down DC-to-DC power μModule® (micromodule) bus converter. The LTM4654’s exposed power inductor resides on the top of the package, providing an intrinsic path for the heat to dissipate up-and-out of the power module—away from the printed circuit board (PCB). The package includes the switching controller IC, the power MOSFETs, and the supporting components. Only flying (charge-pump) capacitors, bulk input and output bypass capacitors, and a few passive components for configurations are needed.

The LTM4654 features bidirectional operation, frequency synchronization, Burst Mode® operation, output voltage soft start, and tracking. An onboard temperature diode is available for temperature monitoring. The LTM4654 is designed for scalability. In higher power applications, multiple LTM4654 power modules can be paralleled.

The LTM4654 protects against short-circuit, overcurrent (OC), and overtemperature (OT) faults. The LTM4654 is offered in a BGA package with a RoHS-compliant terminal finish.

APPLICATIONS

* Non-isolated intermediate bus power architectures

* Telecom, networking, test, and measurement equipment

* Industrial applications

* Input voltage range: 20V to 55V (57V abs. max.)

* Wide output voltage range: 4.5V to 18V (VOUT < VIN/2);

* 96.7% efficiency (9V at ±15A output, 48VIN)

* ±3% maximum total DC output error

* Up to 300W output power (source/sink)

* Scalable for higher power applications

* Fixed-frequency current mode control

* Phase-lockable external synchronization from 200kHz to 1MHz;

* Low startup inrush current with voltage-balancing of CFLY and CMID before the DC-to-DC switching action