New high-density power module technology for FPGAs, SoCs, and ASICs simplifies design.
As semiconductor technology shrinks, it’s becoming increasingly difficult to meet the power demands of integrated circuits (ICs) in less available space. Recent power solutions trade off power density against ease of use, but TDK has created new power modules without these compromises.
TDK’s new μPOL power modules have power circuitry built into a substrate to create a module that can be mounted on either the front or the back of a printed circuit board. This approach realizes an easy-to-use solution delivering 15W in 49 mm3 or 1 watt per cubic millimeter of power.
Ease and speed of design
To use these products, designers need only specify input capacity, output capacity, and—if not using a preset output voltage—a voltage divider, and then match requirements to an available μPOL solution.
Micropower modules are available from 0.6V to 5V output voltage to meet the design requirements of most applications in communication infrastructure, data computing, IoT, embedded vision, real-time signal processing with FPGA, robotics, and AI. TDK provides layout files for the key FPGAs used in these applications.
The path to
power density
These μPOL micropower modules are based on TDK’s proprietary semiconductor embedded substrate (SESUB) technology. Construction begins with an embedded IC, which includes a DC-DC regulator, MOSFETs, and a driver. A copper heat plate is added to the die, embedded for optimal thermal flow from the die to the package, providing 4X to 8X better thermal design than other technologies. This assembly is incorporated directly into a SESUB, four-layer, 300-micron thick substrate.
This approach eliminates the need for troublesome wire bonds and delivers the additional benefit of high reliability against shock and vibration, making the μPOL ideal for industrial and mobile applications like drones. The thermal sink positioned on the bottom of the SESUB allows heat to flow directly into the board for better thermal flow while minimizing the space required. This architecture allows the module to be operated at full-rated current without requiring forced airflow.
Designing with μPOL
TDK provides a power map that identifies the μPOL power module recommended for each voltage rail requirement. It also indicates where common modules can be used in multiple locations on the same design to help reduce costs. Maximum output voltages depend on output currents, and—in analog mode—voltage programming is not necessary; a simple resistor change is all that’s required.
Design tools
TDK has created multiple design tools for designers to use. Information is available at www.us.tdk.com/POL, where users can find starter power schematics and PCB layout templates in Ultra Librarian along with links for:
- AMD Xilinx FPGAs
- Intel Altera FPGAs
- Microchip Devices
- Lattice FPGAs
- Efinix FPGAs
These designs address each of the key power rails, recommend the best module for each power rail, and provide a solution that has been tested by both TDK and the FPGA supplier.
In addition to FPGAs, power schematics for other communication processors and Ethernet chipsets are provided:
- Marvell Armada and Cavium Octeon Arm processors
- NXP LayerScape QoriQ Arm processors
- Broadcom Ethernet controller
- Intel Ethernet controller
- Marvell Ethernet PHY
Selecting components
Once the starter schematic has been chosen, the designer must determine the input and output capacitors. The capacitors provided in the baseline solutions address typical requirements. However, although they have margin built in, they still need to be thoroughly evaluated if VIN is noisy or unstable and/or if VOUT supplies a high transient load.
Designers must determine the actual capacitance value (bulk capacitance for energy storage), the type of capacitor technology to be used, and the allowable parasitic values of the capacitors in terms of equivalent series resistance (ESR) and equivalent series inductance (ESL). Additional output capacitors may be required if the design could experience large di/dt transient events. Resistor divider values should be verified for the final output voltage by point-of-load measurements.
Component design and layout
The distribution of capacitors at the output is also important to minimize circuit board parasitics, as these can impact the speed of supply of stored energy (current) to the electrical load when needed.
Connections to each power plane should be kept simple to ensure no ground loops occur and to avoid parasitic inductances and/or capacitances. It is also recommended that the input communication pins be electrically grounded on the PCB if I2C or PMBUS are not used in the application.
While TDK’s μPOL power modules have current ratings that do not require additional airflow, designers still need to include sufficient PCB thermal vias, properly designed and located, to adequately support the system power while addressing thermal requirements. It is also important to consider copper weight on the PCB and the number of layers, since both impact the thermal performance.
μPOL construction
The 15W-rated modules all have common pinouts and pad layouts for ease of layout. They are available with pre-programmed standard output voltages that reflect the more common voltage rails or, in the case of the FS1406-0600 and FS1412-0600, as customer-configurable output voltage devices using resistors.
Summary
With best-in-class thermal performance and the highest power density for small spaces, TDK’s μPOL power modules offer design and performance advantages while being easy to use and fast to implement.