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Cyclone IV GX FPGA Development Kit Power Supply. Why so sophisticated?

Altera_Forum
Honored Contributor II
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Why Power Supply on "Cyclone IV GX FPGA Development Kit" is so sophisticated? 

Why not use simple 3-pin LDO instead of multi-pin Linear Regulators used on this Kit? 

A picture from "Cyclone IV GX FPGA Development Board Reference Manual" is attached.
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Altera_Forum
Honored Contributor II
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Why Power Supply on "Cyclone IV GX FPGA Development Kit" is so sophisticated? 

 

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What do you consider it sophisticated? The Pin Connection Guidelines for each FPGA describes how Altera recommends powering the FPGA. Multiple linear regulators are required to generate and/or isolate the required voltages. 

 

 

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Why not use simple 3-pin LDO instead of multi-pin Linear Regulators used on this Kit? 

 

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FPGAs have a power-on requirement that the power rails ramp in a well-defined time period. Multi-pin linear regulators generally have enable and soft-start functions that can be used to aid in power-on sequencing. A simple 3-pin linear regulator does not provide this functionality. 

 

Cheers, 

Dave
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Altera_Forum
Honored Contributor II
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--- Quote Start ---  

What do you consider it sophisticated? The Pin Connection Guidelines for each FPGA describes how Altera recommends powering the FPGA. Multiple linear regulators are required to generate and/or isolate the required voltages. 

Dave 

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This one from TI seems much simpler with less BOM and no precision resistors.
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Altera_Forum
Honored Contributor II
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This one from TI seems much simpler with less BOM and no precision resistors. 

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The TI example also does not use 3-pin LDOs :) 

 

Evaluation kits are not necessarily built with the "best" components, they are quite often built with "sponsors" components. Take a look at any of the Altera evaluation boards. For example, several of the kits I have, use Linear Technology parts and have "Linear Technology" on the silk of the PCB. That is there not because Altera loves Linear Technology, but because Linear Technology provided the parts for the evaluation kit :) 

 

The best way to select parts is to ensure that you have design tools for the parts. For example, Linear Technology's LTspice is a very good simulation tool and has an excellent Yahoo support group. 

 

Cheers, 

Dave
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