Dual Loop 8-Phase Step-Down DC/DC Controller with Digital Power System Management

The LTC3888/LTC3888-1/LTC3888-2 is a PMBus-compliant dual loop DC/DC synchronous step-down switching regulator controller with eight expandable phases supporting a wide range of main/subordinate configurations. The controller uses constant frequency current mode architecture to provide excellent transient response and output regulation. Each PWM main is capable of producing output voltages from 0.3 V to 3.45 V with multiple phase configurations using DrMOS devices that provide an output current monitor.

PMBus configuration and monitoring is supported by LTpowerPlay™ software. Programmable loop compensation and built-in load step emulation facilitate setting bandwidth based on input voltage and output load capacitance. PMBus commands allow read back of input voltage, output voltage and current, and operating status. Operating parameters can be set via PMBus command or stored in internal EEPROM for use at power up. Switching frequency, phase configuration, output voltage (LTC3888/LTC3888-2), output current limit (LTC3888-1) and device address can also be set using external programming resistors.

APPLICATIONS

* High Current Distributed Power Systems

* Servers, Network and Storage Equipment

* PMBus/I2C Compliant Serial Interface

* Monitor Voltage, Current, Temperature and Faults

* Digitally Program VOUT, Margins, UV, OV, Current Limit, Soft-Start/Stop and Sequencing

* Expandable to >16 Phases

* 4.5V ≤ VIN ≤ 26.5V, 0.3V ≤ VOUT ≤ 3.45V

* ±0.5% Output Voltage Accuracy

* Programmable PWM Loop Compensation

* Accurate PolyPhase® Current Sharing