Power solution for DDR memory in space applications

This paper describes a radiation hardened by design (RHBD) BUCK switching regulator (Intersil's ISL70003SEH) designed specifically to address powering DDR memory in space applications. Salient features of the design, operation, performance, and radiation characteristics are presented. A report on an example application powering DDR memory is provided. The application utilizes two ISL70003SEH to provide both the main supply (VDDQ) and termination supply (VTT) at 2.5 volt and 1.25 volt respectively from a system bus which may be 3.3V, 5V or 12V input supply. The voltage mode control of the ISL70003SEH provides the necessary ability to source and sink current required for VTT termination.