New Industry Products

# TI’s Stackable DC/DC Buck Converter Maximizes Power Density

March 09, 2020 by Texas Instruments

## This article introduces Texas Instruments new 40-A SWIFT DC/DC buck converter offering first-of-its-kind stackability of up to four integrated circuits (ICs).

Texas Instruments (TI) introduced a new 40-A SWIFTTM DC/DC buck converter, offering first-of-its-kind stackability of up to four integrated circuits (ICs). The TPS546D24A PMBus buck converter can deliver up to 160A of output current at an 85°C ambient temperature – four times more current than competing power ICs. The TPS546D24A has the highest efficiency of any 40-A DC/DC converter, allowing engineers to reduce power loss by 1.5W in a high-performance data center and enterprise computing, medical, wireless infrastructure, and wired networking applications.

### Shrink the Power Supply While Optimizing Thermal Performance

Solution size and thermal performance are two key considerations for engineers designing power supplies for modern field-programmable gate arrays (FPGAs). With its unique stackability, the TPS546D24A buck converter addresses both. It comes with a PMBus interface that offers a selectable internal compensation network, enabling engineers to eliminate as many as six external compensation components from the board and shrink the overall power-supply solution size by more than 10% (or 130 mm2) for higher-current FPGA/application-specific ICs (ASICs) when compared to discrete multiphase controllers.

In addition, the TPS546D24A achieves a low thermal resistance of 8.1°C per watt and runs 13°C cooler than competing DC/DC converters, improving reliability in electronics that operate in hot, harsh environments, such as baseband units and automated test equipment.

### Improve Efficiency at High Switching Frequencies

Using DC/DC converters with high switching frequencies allows engineers to shrink the footprint of the power supply and facilitates the design of high-bandwidth systems. The TPS546D24A offers a switching frequency of 1.5 MHz, enabling engineers to deliver 40 A of current per IC while reducing inductance and capacitance by one-third compared to similar converters. To mitigate the negative impact on efficiency, which is typically associated with high switching frequencies, the TPS546D24A features a 0.9-mΩ low-side MOSFET, achieving 3.5% higher efficiency than competing DC/DC buck converters. For more details on optimizing thermal performance at high switching frequencies, read the technical article, "SoC power design: 3 steps to a thermally optimized power supply."

### Meet Rigorous Voltage Accuracy Requirements for FPGA Power Supplies

FPGAs are used in a variety of applications, but engineers designing power supplies for FPGAs are often surprised by the voltage accuracy required to support FPGA DC rails. The TPS546D24A makes it easier for engineers to meet these rigorous voltage tolerance requirements by offering an output voltage error of less than 1%. Furthermore, its extensive PMBus command set and pin-strapping configurability allow engineers to monitor current more accurately for fault reporting and to avoid overdesign. To learn more about designing power supplies for FPGAs, read the application note "Achieving Better than 1%  Output Voltage Accuracy with TPS546D24A."

### Availability and Pricing

The TPS546D24A is now available from TI and authorized distributors in a 5-mm-by-7-mm, 40-pin quad flat no-lead (QFN) package. The TPS546D24AEVM evaluation module is available on TI.com. Pin-to-pin- and footprint- compatible, preproduction TPS546B24A (20-A) and TPS546A24A (10-A) DC/DC converters are available now, only from TI. Pricing starts at US$3.25 and US$2.49 in 1,000-unit quantities, respectively.

• Download the reference design, "4-phase, 160-A synchronous buck converter reference design for communications processor power."

• Learn about TI’s comprehensive portfolio of high-efficiency DC/DC buck converters.