TL5002 Provides DDR Bus Termination Power Supply Solution
Double data rate (DDR) bus termination power requirements bring new challenges to the power supply by requiring voltage tracking of a reference supply, requiring both sourcing and sinking current, and maintaining a high efficiency over a wide current range. This paper address these issues while presenting an example DDR design of 12 A of output current with voltage outputs between 0.9 V and 1.25 V. Issues and their solutions are provided for the power supply operating as a tradition buck power stage in the sourcing mode as well as for operating as a synchronous boost regulator in the sinking mode. Regulation and control loop characteristics of the examples are presented for both current sinking and sourcing modes of operation. Transient load response is also presented showing output voltage variation, as the current is transitioned from sourcing to sinking. Sufficient design detail is provided to form the basis for a successful DDR power supply.
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