25A Monolithic Synchronous DC/DC Step-Down Converter with PMBus Interface

The LTC7131-1 is a high efficiency, 25A monolithic synchronous buck regulator using a phase lockable controlled on-time, current mode architecture. The output voltage is programmable with a single external resistor or an external voltage reference through the reference input (REF) pin. The output voltage can be margined up or down up to ±25% with 0.1% resolution via a PMBus-compliant serial interface. The serial interface can also be used to read back fault status and both time-averaged (~4ms) and peak input/output current, input/output voltage and temperature. System configuration and monitoring is supported by the LTpowerPlay® development system.

The architecture provides extremely fast response and allows operation at the very low on-times required to regulate low output voltages at high switching frequencies. The operating frequency is programmable from 250kHz to 2MHz with an external resistor or for noise sensitive applications, it can be synchronized to an external clock over the same range.

APPLICATIONS

* Intelligent Energy Efficient Power Conversion

* ASIC/FPGA/Processor Power

* Point of Load Conversion

* 4.5V to 20V VIN Range

* 1% Total VOUT Accuracy Over Temperature

* Single Resistor-Programmable Reference Voltage: 0.4V to 3.5V

* PMBus Compliant Serial Interface:

* Programmable Output Voltage Margining: Up to ±25% VOUT Range with 0.1% Resolution

* Read Back of Average and Peak Temperature, Current, and Voltage (25Hz Refresh Rate)

* Fault Status

* Phase-Lockable Fixed Frequency Up to 2MHz