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Altera_Forum's avatar
Altera_Forum
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15 years ago

DEo NANO VCC noise

hi i have a de0 nano and in the gpio headers i am doing pwm at 50MHZ...it have 2 gpio headers of 40 pins .. and i notice that when they are the same ... in the VCC_SYS appear a noise almost 2 Vpp... ...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
15 years ago

Yes i am using an USB cable from about 1.4 m ...to supply the board ... to reduce the noise i have to put a 100 nF capacitor outside the board between ground and Vcc_SYS.. these are 2 pins from one of the GPIO header... and the pics of the noise reduce to 900 Vpp "pic to pic" ... still big ..

Do you think that the usb is making noise ?

Thankyou!