Nexys A7 Supply voltage problem-wiring resistance

[marimo]

Hi,

I have a Nexys A7-100T board. I want to supply voltage using external battery pack for my measurement.

But for my measurement setting,voltage supply line has 6.5Ω resistance.When I supplied 5 V to voltage supply line, FPGA coundn 't activated.

I guessed the reason for activation problem is voltage drop. I supplied about 7.25 voltage so that voltage between battery’s positive terminal to the center pin of JP3 and the negative terminal to the pin labeled J12 is about 5 voltage.I checked the center pin of JP3 and the pin of J12 is about 5V. But I coundn 't activated.

Why  coundn 't I activate Nexys A7-100T?

Circuit_schematic.bmp

 

 

 

[zygot]

11 hours ago, marimo said:

But for my measurement setting,voltage supply line has 6.5Ω resistance.When I supplied 5 V to voltage supply line, FPGA coundn 't activated.

This needs to be clarified. I assume that what you mean is that with your setup you were unable to configure the FPGA.

What are you trying to measure?

Where does your schematic show what you refere to as a 6.5 ohm supply line?

Did you check that all power supply voltages are present?

Experimenting with stuff that you don't understand can result in damage to equipment.

[marimo]

Hi

What are you trying to measure?

→I want to use Nexys A7-100T in the container. But for my measurement setup, I can use only 6.5 ohm cable line to supply voltage to Nexys A7-100T.

Where does your schematic show what you refere to as a 6.5 ohm supply line?

→6.5 ohm is cable resistance from end to end. I checked cable resistance with multimeter.

Did you check that all power supply voltages are present?

→Yes.Voltage supply output setting values.

 

[zygot]

Not sure what you mean by "I want to use Nexys A7-100T in the container"... must be a language barrier issue.

6.5 ohms seems to be rather high and likely problematic; A 5V voltage source with a 6.5 ohm output impedance can only provide < 800 ma of current. Have you consulted the Nexys A7 Reference Manual Power Supplies section?

 

[JColvin]

Hi @marimo,

When you say not activated, do you mean that when you attached your battery power to the Nexys A7 (with the positive power in the center of JP3 and the negative source on the single J12 pin) and turned on the power switch, LD22 did not turn on nor was the board able to been seen by the host computer when connected by the USB cable?

As per the Power Supplies section of the reference manual, the out-of-box demo only draws about 400 mA, so even with the quoted line resistance there should be some response from the board. Have you configured the board with a different project? Are you able to run the board normally if you set the jumper to have the board powered from USB? What jumper setting do you have on JP1 (the mode jumper)?

Additionally, I am concerned about the when you supplied the 7.25V on the battery terminals; the primary regulator cannot handle voltages over 5.5V so the board may have been damaged at that point.

Thanks,
JColvin