
Stackable 40A DC-DC converter targets high-current FPGAs and processors
Texas Instruments (TI) has launched a 40A DC-DC converter that be stacked up to four high.
Four of the SWIFT TPS546D24A DC-DC buck converters can be controlled via a PMbus link to provide up to 160 A of output current at an 85°C ambient temperature – four times more current than other power ICs. A 0.9-mΩ low-side and 4.5-mΩ high side MOSFETs allow engineers to reduce power loss by 1.5W in high-performance data centre and enterprise computing, medical, wireless infrastructure, and wired networking applications.
The DC-DC converter has an option to overdrive the internal 5V low drop out regulator (LDO) with an external 5V supply via the VDD5 pin to improve efficiency and reduce power dissipation of the converter.
The PMBus interface has 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 size by more than 10 per cent, or 130 mm2 for higher-current FPGA or ASICs compared to discrete multiphase controllers.
The 1.5MHz fixed frequency current mode control of the DC-DC converter allows smaller inductors to be used, and the design reduces inductance and capacitance by one-third compared to similar converters.
The TPS546D24A DC-DC converter supports rigorous voltage tolerance requirements for FPGA designs through an output voltage error of less than 1 percent. The PMBus command set and pin-strapping configurability allows engineers to monitor current more accurately for fault reporting and to avoid overdesign. Achieving Better than 1% Output Voltage Accuracy with TPS546D24A.
The PMBus interface with 1MHz clock support gives a standardised digital interface for converter configuration as well as monitoring of key parameters including output voltage, output current, and internal die temperature. Response to fault conditions can be set to restart, latch off, or ignore, depending on system requirements. Back-channel communication between stacked devices enables all TPS546D24A converters powering a single output rail to share a single address to simplify system software/firmware design.
Key parameters including output voltage, switching frequency, soft-start time, and overcurrent fault limits can also be configured through BOM selection without PMBus communication to support program free power-up.
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. Pricing starts at US$4.27 in 1,000-unit quantities.
The TPS546D24AEVM evaluation module is available on TI.com for US$199. Pin-to-pin- and footprint- compatible, preproduction TPS546B24A (20A) and TPS546A24A (10A) 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.
A reference design shows a 4-phase, 160-A synchronous buck converter reference design for communications processor power
