CSD87331Q3D

www.ti.com

SLPS283A

– SEPTEMBER 2011 – REVISED JANUARY 2012

APPLICATION INFORMATION

Equivalent System Performance

Many of today

’s high performance computing systems require low power consumption in an effort to reduce

system operating temperatures and improve overall system efficiency. This has created a major emphasis on

improving the conversion efficiency of today

’s Synchronous Buck Topology. In particular, there has been an

emphasis in improving the performance of the critical Power Semiconductor in the Power Stage of this

Application (see Figure 28). As such, optimization of the power semiconductors in these applications, needs to

Figure 28.

The CSD87331Q3D is part of TI

’s Power Block product family which is a highly optimized product for use in a

synchronous buck topology requiring high current, high efficiency, and high frequency. It incorporates TI

’s latest

generation silicon which has been optimized for switching performance, as well as minimizing losses associated

eliminating parasitic elements between the Control FET and Sync FET connections (see Figure 29). A key

challenge solved by TI

’s patented packaging technology is the system level impact of Common Source

Inductance (CSI). CSI greatly impedes the switching characteristics of any MOSFET which in turn increases

switching losses and reduces system efficiency. As a result, the effects of CSI need to be considered during the

MOSFET selection process. In addition, standard MOSFET switching loss equations used to predict system

efficiency need to be modified in order to account for the effects of CSI. Further details behind the effects of CSI

and modification of switching loss equations are outlined in TI

’s Application Note SLPA009.

Figure 29.

Copyright

© 2011–2012, Texas Instruments Incorporated

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