LTM4638

Demonstration circuit 2665B-B features the LTM4638 μModule^® regulator, a high performance, high efficiency step-down regulator. The LTM4638 is a complete DC/DC point-of-load regulator in a thermally enhanced 6.25mm × 6.25mm × 5.02mm BGA package. The LTM4638 has an operating input voltage range of 3.1V to 20V and provides an output current up to 15A. The output voltage is programmable from 0.6V to 5.5V and can be remotely sensed. The stacked inductor design improves thermal dissipation and significantly reduces the package area. Output voltage tracking is available through the TRACK/ SS pin for supply rail sequencing. External clock synchronization is available through the SYNC/MODE pin. For high efficiency at low load currents, select discontinuous current mode (DCM) operation using the MODE jumper (JP7) in less noise sensitive applications. Refer to the LTM4638 data sheet in conjunction with the demo manual for working on or modifying the DC2665B-B.

Demonstration circuit 2665B-B features the LTM4638 μModule^® regulator, a high performance, high efficiency step-down regulator. The LTM4638 is a complete DC/DC point-of-load regulator in a thermally enhanced 6.25mm × 6.25mm × 5.02mm BGA package. The LTM4638 has an operating input voltage range of 3.1V to 20V and provides an output current up to 15A. The output voltage is programmable from 0.6V to 5.5V and can be remotely sensed. The stacked inductor design improves thermal dissipation and significantly reduces the package area. Output voltage tracking is available through the TRACK/ SS pin for supply rail sequencing. External clock synchronization is available through the SYNC/MODE pin. For high efficiency at low load currents, select discontinuous current mode (DCM) operation using the MODE jumper (JP7) in less noise sensitive applications. Refer to the LTM4638 data sheet in conjunction with the demo manual for working on or modifying the DC2665B-B.

This evaluation board is obsolete and no longer recommended. The replacement board is the DC2665B-B.

Demonstration circuit 2665A-B features the LTM4638 µModule^® regulator, a high performance, high efficiency step-down regulator. The LTM4638 is a complete DC/DC point-of-load regulator in a thermally enhanced 6.25mm × 6.25mm × 5.02mm BGA package. The LTM4638 has an operating input voltage range of 3.1V to 20V and provides an output current up to 15A. The output voltage is programmable from 0.6V to 5.5V and can be remotely sensed. The stacked inductor design improves thermal dissipation and significantly reduces the package area. Output voltage tracking is available through the TRACK/SS pin for supply rail sequencing. External clock synchronization is available through the SYNC/MODE pin. For high efficiency at low load currents, select DCM mode operation using the MODE jumper (JP7) in less noise sensitive applications. The LTM4638 data sheet must be read in conjunction with this demo manual for working on or modifying DC2665A-B.

This evaluation board is obsolete and no longer recommended. The replacement board is the DC2665B-B.

Demonstration circuit 2665A-B features the LTM4638 µModule^® regulator, a high performance, high efficiency step-down regulator. The LTM4638 is a complete DC/DC point-of-load regulator in a thermally enhanced 6.25mm × 6.25mm × 5.02mm BGA package. The LTM4638 has an operating input voltage range of 3.1V to 20V and provides an output current up to 15A. The output voltage is programmable from 0.6V to 5.5V and can be remotely sensed. The stacked inductor design improves thermal dissipation and significantly reduces the package area. Output voltage tracking is available through the TRACK/SS pin for supply rail sequencing. External clock synchronization is available through the SYNC/MODE pin. For high efficiency at low load currents, select DCM mode operation using the MODE jumper (JP7) in less noise sensitive applications. The LTM4638 data sheet must be read in conjunction with this demo manual for working on or modifying DC2665A-B.

• Current Mode Control
  • Good Current Sharing
• External Frequency Synchronization
• Differential Remote Sensing

The EVAL-LTM4638-AZ evaluation board is a power supply generating 1V, 60A (max) from a 3.1V to 20V input. It is a quad PolyPhase® solution featuring the LTM®4638, a high-performance and high-efficiency step-down regulator. The LTM4638 is a complete DC-to-DC point-of-load (POL) regulator in a thermally enhanced 6.25mm × 6.25mm × 5.02mm BGA package.

The EVAL-LTM4638-AZ is optimized using a default frequency of 600kHz, and the current mode control architecture allows easy current sharing. The LTM4638 operates in continuous-conduction mode (CCM) by default but can be placed in pulse-skipping mode (PSM) to optimize efficiency at light loads.

An external clock IC, LTC6902, is included in the EVAL-LTM4638-AZ and is used to provide clock synchronization signals to interleave the four channels 90° out-of-phase for reduced root mean square (RMS) input current ripple and output voltage ripple. The LT3088 is also included in this solution to power the clock IC.

The LTM4638 data sheet gives a complete description of the device, including operation and application information. The data sheet must be read in conjunction with this evaluation board user guide prior to working on or modifying the EVAL-LTM4638-AZ.

• Current Mode Control
  • Good Current Sharing
• External Frequency Synchronization
• Differential Remote Sensing

The EVAL-LTM4638-AZ evaluation board is a power supply generating 1V, 60A (max) from a 3.1V to 20V input. It is a quad PolyPhase® solution featuring the LTM®4638, a high-performance and high-efficiency step-down regulator. The LTM4638 is a complete DC-to-DC point-of-load (POL) regulator in a thermally enhanced 6.25mm × 6.25mm × 5.02mm BGA package.

The EVAL-LTM4638-AZ is optimized using a default frequency of 600kHz, and the current mode control architecture allows easy current sharing. The LTM4638 operates in continuous-conduction mode (CCM) by default but can be placed in pulse-skipping mode (PSM) to optimize efficiency at light loads.

An external clock IC, LTC6902, is included in the EVAL-LTM4638-AZ and is used to provide clock synchronization signals to interleave the four channels 90° out-of-phase for reduced root mean square (RMS) input current ripple and output voltage ripple. The LT3088 is also included in this solution to power the clock IC.

The LTM4638 data sheet gives a complete description of the device, including operation and application information. The data sheet must be read in conjunction with this evaluation board user guide prior to working on or modifying the EVAL-LTM4638-AZ.

• Analog Devices has worked closely with Intel PSG to develop verified power solutions that optimize cost, size and efficiency in high performance applications.
• The validated power solutions include uModules power products that address time and space constraints while delivering high efficiency, reliability, and low noise.
• The actual power tree represents the best solution at time of design.
• A recommended power tree has also been included to present the ideal solution at time of Stratix 10 GX PCIe development kit release. An updated alternate version of the power tree represents the latest solutions available from Analog Devices. For many applications, an intermediate rail is not ideal, so recommendations an alternate power tree that allow for direct power conversion from 12V input is provided below.

• Analog Devices has worked closely with Intel PSG to develop verified power solutions that optimize cost, size and efficiency in high performance applications.
• The validated power solutions include uModules power products that address time and space constraints while delivering high efficiency, reliability, and low noise.
• The actual power tree represents the best solution at time of design.
• A recommended power tree has also been included to present the ideal solution at time of Stratix 10 GX SI development kit release. An updated alternate version of the power tree represents the latest solutions available from Analog Devices. For many applications, an intermediate rail is not ideal, so recommendations for an alternate power tree that allows for direct power conversion from 12V input is provided below.

The HTG-937 provides access to large FPGA gate density and 8GB/16GB of high bandwidth memory. It is populated with the Xilinx Zynq Virtex Ultrascale VU37P, or VU47P. Analog Devices power solution on this platform is fully validated to meet the requirements of Xilinx Zynq Virtex Ultrascale FPGAs to ensure a robust power delivery solution.

DC/DC μModule regulators are used on the HTG-937 to power Xilinx FPGA and/or SoC rails as well as other system rails. These regulators are highly integrated solutions with built in controller, power FETs, inductors, and capacitors that simplify layout and provide robust power delivery performance.

We provide supporting documentation including power schematics, layout, LTpowerPlanner and applicable LTpowerPlay configuration files to enable you to validate the power solution for your application seamlessly.

• Xilinx Versal^™ AI Core and Prime series solves a broad range of industry-specific problems with performance and flexibility. Core use cases  include storage acceleration,  data center network acceleration, 5G xHaul and Passive optical networks.


• The HTG-VSL1 AI Core and Prime PCIe express platform allows easy and versatile functional expansion through two Vita 57.4 compliant High-Pin-Count  FMC+ ports and one high-speed AcceleRate^® port.


• Analog Devices, Inc. supports power delivery solutions for the HTG-VSL1 for the Versal AI Core and Versal Prime PCIe express platform. DC/DC μModule regulators are used on the HTG-VSL1 to power Xilinx FPGA and/or SoC rails as well as other system rails. These regulators are highly integrated solutions with built in controller, power FETs, inductors, and capacitors that simplify layout and provide robust power delivery performance.


• ADI provides supporting documentation including power schematics, layout, LTpowerPlanner^® and applicable LTpowerPlay^® configuration files to enable you to validate the power solution for your application seamlessly.


• For a complete list power designs and use cases, please contact your local FAE.


• Key Power DC DC Modules include:
• LTM4700 is a Dual 50A or Single 100A μModule Regulator with Digital Power System Management, PMBus
• LTM4638 is a 15A Step-Down DC/DC μModule Regulator
• LTM4625 is a 5A Step-Down DC/DC μModule Regulator
• LTM4632 is a Triple Output, Step-Down μModule Regulator for DDR-QDR4 Memory
• LTC2937 is a Programmable Six Channel Sequencer and Voltage Supervisor with EEPROM