Features and Benefits
- 4.7V to 15V Input Voltage Range
- 0.6V to 1.8V Output Voltage Range
- 25A DC Output Current
- 1.2% Total DC Output Voltage Error (–40°C to 125°C)
- High Reliability N + 1 Phase Redundancy Supported
- Internal or External Control Loop Compensation
- Differential Remote Sense Amplifier for Precision Regulation
- Current Mode Control/Fast Transient Response
- Multiphase Current Sharing Up to 150A
- Built-In Temperature Monitoring
- Selectable Pulse-Skipping, Burst Mode® Operation
- Soft-Start/Voltage Tracking
- Frequency Synchronization
- Output Overvoltage Protection
- Output Overcurrent Foldback Protection
- 9mm × 15mm × 3.51mm BGA Package
The LTM4645 is a 25A output switching mode step-down DC/DC µModule® (power module) regulator. Included in the package are the switching controller, power FETs, inductor and all supporting components. Operating over an input voltage range of 4.7V to 15V, the LTM4645 supports an output voltage range of 0.6V to 1.8V, set by a single external resistor. Only a few input and output capacitors are needed.
Its high efficiency design delivers about 86% efficiency from 12V input to 1.0V output with 25A continuous load current. High switching frequency and a current-mode architecture enable a very fast transient response to line and load changes without sacrificing stability. The device supports frequency synchronization, programmable multiphase operation, N+1 phase redundancy, and output voltage tracking for supply rail sequencing.
Fault protection features include overvoltage and overcurrent protection. The power module is offered in a space saving 9mm × 15mm × 3.51mm BGA package. The LTM4645 is available with SnPb (BGA) or RoHS compliant terminal finish.
- Telecom, Networking and Industrial Equipment
- Point of Load Regulation
Product Lifecycle Production
At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.
Evaluation Kits (1)
Demonstration circuit 2616A-A features a polyphase design using the LTM4645EY, a 25A high efficiency, switch mode step-down power µModule regulator. The input voltage range is from 6V to 15V. To use DC2616A-A for input voltage range from 4.7V to 6V, connect INTVCC to SVIN (change R22, R42 from OPT to 0Ω), DRVCC to VIN (change R21, R38 from 0Ω to OPT, R2, R39 from OPT to 0Ω). The output voltage range is 0.6V to 1.8V. The DC2616A-A can deliver a nominal 50A output current. As explained in the data sheet, output current derating is necessary for certain VIN, VOUT, and thermal conditions. The board operates in continuous conduction mode in heavy load conditions. For high efficiency at low load currents, the MODE_PLLIN jumper selects pulse-skipping mode for noise sensitive applications or burst mode operation in less noise sensitive applications. The MODE_PLLIN pin also allows the LTM4645 to synchronize to an external clock signal. The phase shift between the two phases is 180 degrees. DC2616A-A has the option of choosing both internal and external compensation circuit for LTM4645. The LTM4645 data sheet must be read in conjunction with this demo manual prior to working on or modifying demo circuit DC2616A-A.
Tools & Simulations
LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.
Models for the following parts are available in LTspice:
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:
LTM4645 Companion Parts
Recommended Related Parts
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.