Intersil Power Management Solutions for Xilinx FPGAs

Application Guide: Intersil Solutions for Precise Power Delivery to Xilinx FPGAs

Intersil's Family of Integrated FET Regulators:
EL7566: Monolithic 6A DC/DC Step-Down Regulator

ISL65426: 6A Dual Synchronous Buck Regulator with Integrated MOSFETs

ISL6521: PWM Buck DC/DC and Triple Linear Power Controller

ISL644x: Step-Down PWM Controllers

ISL6420A: PWM Controller with Wide VIN, Start-Up into Pre-Bias Load

ISL8102: Two-Phase Buck PWM Controller with High Current Integrated MOSFET Drivers

Intersil Power Management Solutions for Xilinx FPGAs

Typical Field Programmable Gate Array (FPGA) Power Requirements

The flexibility of FPGAs leads to the requirement for multiple supply voltages and currents.

Core Voltage/Power
In large FPGAs and CPLDs, the logic core generally has the most demanding current requirements, up to tens of amps depending on the number of gates being used and the clock frequency. See the table below for designated core voltage required by the different Xilinx platforms.

Xilinx Devices Virtex® Series

Spartan® Series

CoolRunner™ Series

XC9500 Series

V_CCINT 1/1.2/1.5/1.8V 1.2V 1.8/3.3V 2.5/3.3/5V

V_CCO/VCCIO 1.2, 1.5, 1.8, 2.5, 3.3V 1.2, 1.5, 1.8, 2.5, 3.3V 1.5, 1.8, 2.5, 3.3, 5V 1.8, 2.5, 3.3, 5V

V_CCAUX 2.5/3.3V 2.5/3.3V - -

I/O Voltage/Power
Designated V_CCIO/VCCO and equal to 1.2V, 1.5V, 1.8V, 2.5V, 3.3V or 5V, depending on the I/O standard selected. I/O standards can be set independently by block in the FPGA and CPLD, so more than one I/O voltage for a single FPGA/CPLD is possible.

V_AUX Voltage/Power
The “auxiliary” supply is important for the latest generation of Xilinx FPGAs because it is tied into the JTAG, DCM, and other circuitry. It is designated V_CCAUX, and is usually 3.3V or 2.5V. V_CCAUX must be sufficiently decoupled in order to avoid power supply transients coupling into the FPGA’s clock circuitry.

Xilinx, the Xilinx logo, Virtex, and Spartan are registered trademarks of Xilinx in the United States and other countries. CoolRunner is the registered trademark of Xilinx in the United States.