Synchronous step-down DC/DC controller features I2C/PMBus digital power system management and onboard EEPROM

August 24, 2012 // By Paul Buckley
Linear Technology Corporation has unveiled a synchronous step-down DC/DC controller with an I2C-based PMBus interface for digital power system management.

The LTC3883/-1 combines best-in-class current-mode switching regulator performance with precision mixed signal data acquisition for unsurpassed ease of power system design and management. The device is supported by the LTpowerPlay software development system via an easy-to-use graphical user interface (GUI).

The LTC3883 allows for digital programming and read back for real-time control and monitoring of critical point-of-load converter functions. Programmable control parameters include output voltage, margining and current limits, input and output supervisory limits, switching frequency and tracking. On-chip precision data converters and EEPROM enable the capture and non-volatile storage of regulator configuration settings and telemetry variables, including input voltage and current as well as output voltage and current, duty cycle, temperature and fault logging.

Configurations for the LTC3883 are easily saved to the internal EEPROM over the device’s I2C serial interface, using Linear Technology’s LTpowerPlay GUI-based development software. With configurations stored on-chip, the controller can power-up autonomously without burdening the host processor. Default settings can be optionally configured by external resistor dividers for output voltage, switching frequency, phase and device address. Multiple designs can be easily calibrated and configured in firmware to optimize a single hardware design for a range of applications.

The LTC3883 can be configured for up to 6 phases that can be interleaved and paralleled for accurate sharing among multiple ICs, minimizing input and output filtering requirements for high current and/or multiple output requirements. Applications include high current ASIC, FPGA and processor supplies in telecom, datacom, computing and storage markets.

The LTC3883 features high current integrated gate drivers to drive N-channel power MOSFETs from input voltages ranging from 4.5 V to 24 V. It can produce ± 0.50% accurate output voltages from 0.5 V to 5.5 V with output currents up to 30 A per phase over the full operating temperature range. An integrated amplifier provides true differential remote output voltage sensing, enabling high accuracy regulation, independent of board IR voltage drops. Highest efficiency is achieved