Features and Benefits
- PMBus/I2C Compliant Serial Interface
- Telemetry Read-Back IncludesVIN, IIN, VOUT, IOUT, Temperature and Faults
- Programmable Voltage, Current Limit, Digital Soft-Start/Stop, Sequencing, Margining, OV/UV/OC, Frequency, and Control Loop Compensation
- Output Error Less Than ±0.5% Over Temperature
- Integrated 16-Bit ADC and 12-Bit DAC
- Integrated High Side Current Sense Amplifier
- Internal EEPROM with ECC and Fault Logging
- Integrated N-Channel MOSFET Gate Drivers
- WideVIN Range: 5Vto 60V
- VOUT0, VOUT1 Range: 1V to 40V
- Analog Current Mode Control
- Accurate PolyPhase® Current Sharing for Up to 6 Phases (85kHzt o 500kHz)
- Available in a 52-Lead (7mm× 8mm) QFN Package
The LTC3889 is a dual PolyPhase DC/DC synchronous step-down switching regulator controller with I2C-based PMBus compliant serial interface. This controller employs a constant-frequency, current-mode architecture, with high voltage input and output capability along with programmable loop compensation. The LTC3889 is supported by the LTpowerPlay™ software development tool with graphical user interface (GUI).
The EXTVCC pin supports voltages up to 14V allowing for optimized circuit efficiency and die temperature, and for the controller output to supply the chip power. Switching frequency, output voltage, and device address can be programmed both by digital interface as well as external configuration resistors. Parameters can be set via the digital interface or stored in EEPROM. Both outputs have an independent power good indicator and FAULT function.
The LTC3889 can be configured for discontinuous (pulseskipping) mode or continuous inductor current mode.Applications
- Telecom, Datacom, and Storage Systems
- Industrial and Point of Load Applications
Product Lifecycle Recommended for New Designs
This product has been released to the market. The data sheet contains all final specifications and operating conditions. For new designs, ADI recommends utilization of these products.
Evaluation Kits (1)
Demonstration circuit 2595A is a high voltage, dual output step-down synchronous buck converter featuring the LTC3889EUKG, a 60V dual-phase current mode controller. The LTC3889 has the PMBus interface and the power system management functions.
The DC2595A uses discrete MOSFET as the power stage. The input range of this board is from 36V to 54V, and the default outputs are 12V/20A (VOUT0) and 24V/20A (VOUT1). DC2595A also has an on-board dynamic load circuit, which makes it easy for the customer to evaluate the transient performances.
Please be aware that the DC2595A default connects VOUT0 (12V) to the LTC3889 EXTVCC pin through R168. As a result, the DRVCC can be adjusted to 6.3V, 7.4V or 9V by setting DRVSET to 0, 1 or 2 in LTpowerPlay®. If you want to adjust VOUT0 to a voltage higher than 12V, R168 must be removed first to avoid damaging the IC.
The DC2595A powers up to default settings and produces power based on configuration resistors or NVM without the need for any serial bus communication. This allows easy evaluation of the DC/DC converter aspects of the LTC3889. To fully explore the extensive power system management features of the parts, download the GUI software LTpowerPlay onto your PC and use LTC’s I2C/SMBus/PMBus Dongle DC1613A to connect to the board. LTpowerPlay allows the user to reconfigure the part on-the-fly and store the configuration in EEPROM, view telemetry of voltage, current, temperature and fault status.
Tools & Simulations
LTpowerCAD® is a power supply design program which selects power stage components, provides detailed power efficiency, shows quick loop Bode plot stability and load transient analysis, and can export to LTspice for simulation.
Design tools for the following parts are available in LTpowerCAD:
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal.
Sample & Buy
The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.