Features and Benefits
- Complete 20A Switch Mode Power Supply
- 2.375V to 7V Input Voltage Range (VIN < 4.5V, Need CPWR Bias)
- 0.6V to 5.5V Output Voltage Range
- ±1.5% Maximum Total DC Output Voltage Error (–40°C to 125°C)
- Differential Remote Sense Amplifier for Precision Regulation (VOUT ≤ 3.3V)
- Current Mode Control/Fast Transient Response
- Parallel Multiphase Current Sharing (Up to 80A)
- Frequency Synchronization
- Selectable Pulse-Skipping or Burst Mode® Operation
- Soft-Start/Voltage Tracking
- Up to 88% Efficiency (3.3VIN, 1.5VOUT)
- Overcurrent Foldback Protection
- Output Overvoltage Protection
- Internal Temperature Monitor
- Overtemperature Protection
- 15mm × 15mm × 4.92mm BGA Package
The LTM4639 is a complete 20A output high efficiency switch mode step-down DC/DC μModule (power module) regulator. Included in the package are the switching controller, power FETs, inductor and compensation components. Operating over an input voltage range from 2.375V to 7V, the LTM4639 supports an output voltage range of 0.6V to 5.5V, set by a single external resistor. Only a few input and output capacitors are needed.
Current mode operation allows precision current sharing of up to four LTM4639 regulators to obtain up to 80A output. 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, multiphase/current sharing, Burst Mode operation and output voltage tracking for supply rail sequencing. A diode-connected PNP transistor is included for use as an internal temperature monitor. For up to 20V input operation, please see the LTM4637.
The LTM4639 is offered in a 15mm × 15mm × 4.92mm BGA package. The LTM4639 is RoHS compliant.
- Telecom Servers and Networking Equipment
- Industrial Equipment
- Medical Systems
- High Ambient Temperature Systems
- 3.3V Input Systems
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 2166A features the LTM4639EY, a 20A high efficiency, switch mode step-down power μModule® regulator. The input voltage range is from 2.375V to 7V. The output voltage range is 0.6V to 5.5V. Derating is necessary for certain VIN, VOUT, frequency and thermal conditions. The DC2166A offers the TRACK/SS pin allowing the user to program output tracking or soft-start period. The board operates in continuous conduction mode in heavy load conditions. For high efficiency at low load currents, the MODE jumper (JP3) selects pulse-skipping mode for noise sensitive applications or Burst Mode® operation in less noise sensitive applications. There is an on board boost circuit using LT1935 to provide control power to LTM4639 when VIN is less than 4.5V. LTM4639 has on board diode connected PNP transistors to monitor its internal temperature. A temperature sensor LTC2997 converts the internal temperature to an analog voltage output. The LTM4639 data sheet must be read in conjunction with this demo manual prior to working on or modifying demo circuit DC2166A.
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.
To launch ready-to-run LTspice demonstration circuits for this part:
Step 1: Download and install LTspice on your computer.
Step 2: Click on the link in the section below to download a demonstration circuit.
Step 3: If LTspice does not automatically open after clicking the link below, you can instead run the simulation by right clicking on the link and selecting “Save Target As.” After saving the file to your computer, start LTspice and open the demonstration circuit by selecting ‘Open’ from the ‘File’ menu.
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.
To open the project file for this circuit:
Step 1: Download and install LTpowerCAD on your computer.
Step 2: Click on the link(s) in the section below to download part-specific project files.
Step 3: If the project file doesn't run, right-click the link and select "Save Target As." Then start the LTpowerCAD tool and open the project file by selecing "Open Project" from the "File" menu.
LTpowerCAD Project Files
Design tools for the following parts are available in LTpowerCAD:
LTM4639 Companion Parts
Recommended Related Parts
Product Selector Card (2)
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.