August 24, 2012 – Linear Technology Korea (CEO Hong Sa-kwak) announced the release of a synchronous step-down DC/DC controller (Product Name: LTC3883/-1) featuring an I2C-based PMBus interface suitable for digital power system management. This device combines best-in-class current mode switching regulator performance with precise mixed-signal data acquisition capabilities to provide highly convenient support for the design and management of power systems. This product utilizes the LTpowerPlay™ software development system with an easy-to-use graphical user interface (GUI).
The LTC3883 is digitally programmable and reverse-readable, enabling real-time control and monitoring of critically important point-of-load (PoL) converter functions. Programmable control parameters include output voltage, margining and current limits, input and output supervised limits, switching frequency, and tracking functions. The on-chip precision data converter and EEPROM enable non-volatile storage by capturing regulator configuration settings and telemetry variables, including input and current as well as output voltage and current, duty cycle, temperature, and error logging.
The configuration of the LTC3883 can be easily saved from the device's I2C serial interface to the internal EEPROM using Linear Technology's LTpowerPlay GUI-based development software. Through the on-chip configuration, this controller can operate automatically without burdening the host processor. Error settings can be selectively configured via an external register divider based on output voltage, switching frequency, phase, and device address. Multiple designs can be easily corrected and configured via firmware, optimizing a single hardware design suitable for a wide range of applications.
The LTC3883 can be configured with up to 6 phases, so it can be interleaved and parallelized for accurate sharing among multiple ICs. Accordingly, input and output filtering requirements for high current and multiple outputs are minimized. Applications include high-current ASICs, FPGAs, and processor power supplies used in the telecom, datacom, computing, and storage markets.
The LTC3883 features a high-current integrated gate driver to drive N-channel power MOSFETs across an input voltage range of 4.5V to 24V. Utilizing up to 30A output current per phase across the entire operating temperature range, it can generate output voltages with ±0.50% accuracy from 0.5V to 5.5V. The highly integrated amplifier provides true differential remote output voltage sensing, enabling high-accuracy regulation that is independent of board IR voltage drop. High-efficiency performance is achieved by sensing current using the voltage drop across the output inductor (DCR). Alternatively, an external sense resistor can be used optionally. Programmable DCR temperature compensation maintains accurate and constant current limits across the board temperature range. With a minimum device on-time of just 90nsec, the LTC3883/-1 is ideal for compact, high-efficiency, high-step-down ratio applications. Precise timing for multi-chip and event- or time-based sequencing can optimize power-up and power-down in complex, multi-rail systems. Additional features include storage for data verification and tracking, periodic current limiting, adjustable soft start, synchronizable switching frequency, and programmable GPIO pin functions, which indicate component status and provide automatic recovery in the event of a failure.
The LTC3883 provides onboard LDO features suitable for controllers and gate drive power, while the LTC3883-1 enables external bias for maximum efficiency. Both components are supplied in a thermally enhanced 5mm x 5mm QFN-32 package. The extended temperature range grade provides an operating junction temperature range of -40°C to 105°C. Industrial-grade components provide an operating junction temperature range of -40°C to 125°C. Pricing starts at $4.82 each for quantities of 1,000, and both products are available immediately. For more information, see www.linear.com/product/LTC3883 .

Photo Caption: I2C/PMBus Synchronous Step-Down DC/DC Controller

Product Features: LTC3883/-1

• Synchronous step-down DC/DC controller with powerful onboard N-channel MOSFET driver
• I2C/PMBus compatible serial interface
• Built-in non-volatile EEPROM memory
• Programmable parameters: Includes VOUT, ILIM, sequencing margin, OV/UV level, switching frequency & current limit
• System management telemetry variables: include VIN, IIN, VOUT, IOUT, duty cycle, temperature, fault status, and logging functions.
• VOUT Range: 0.5V ~ 5.5V
• ±0.5% maximum DC output voltage error over the entire operating junction temperature range
• Temperature-compensated DCR or RSENSE current detection
• PolyPhase® motion for up to 6 faces
• PLL (Phase-Locked Loop) fixed frequency ranging from 250kHz to 1MHz