20/30A PMBus converters lower EMI, support adaptive voltage scaling

August 04, 2015 // By Graham Prophet
20-A and 30-A synchronous DC/DC buck converters offer frequency synchronisation for low-noise and reduced EMI/EMC; and a PMBus interface for adaptive voltage scaling (AVS).

Texas Instruments’s SWIFT 20-A TPS544B25 and 30-A TPS544C25 converters integrate MOSFETs and feature small PowerStack QFN packages to drive ASICs in space-constrained and power-dense applications. Design support comes with TI’s WEBENCH online design tools.

The highly integrated converters feature 0.5% reference-voltage accuracy and full differential remote-voltage sensing to meet the voltage requirements of deep sub-micron processors. Frequency synchronisation to an external clock eliminates beat noise and reduces EMI. TPS544B25 and TPS544C25 offer pin-strapping that enables the devices to start up without PMBus commands, to an output voltage set by a single resistor. Programmability, real-time monitoring of the output voltage, current and external temperature, and fault reporting via PMBus simplify power-supply design, increase reliability, and reduce component count and system cost.

TPS544B25 and TPS544C25 features include;

- Integrated power MOSFETs support 20-A and 30-A of continuous output current.

- On-chip PMBus interface and non-volatile memory simplify power-supply design and enable customisation.

- Voltage-control mode with input feed-forward improves noise margin and responds quickly to input voltage changes. A related video is here.

- Other features include internal soft start, input under-voltage protection, thermal shutdown and a reset function.

Packaged in a 40-pin, 5 x 7-mm by 1-mm profile PowerStack QFN package, the 20-A TPS544B25 is priced at $4.08 and the 30-A TPS544C25 is priced at $4.49 (each 1000). An evaluation module is available for the TPS544B25 and TPS544C25.

Supporting documentation includes Selecting the correct PMBus POL solution for your application ” and PMBus – what is the value anyway?