daleye
Newbie level 3
Need some help confirming my thoughts/advising on the mitigation for an existing system design that is having susceptibility issues.
Side A:
Voltage Reg
Reference Ground
LVDS receiver
Outer most shield tied to earth through safety capacitors
LVDS lines shield (within the outer most shield) tied to Reference ground
Side B:
Digital circuitry
LVDS transmitter
Reference ground brought to this circuit by means of the LVDS shield
Outer most shield floating (no connection)
Cable:
"Safety Cap" shield encloses:
My thoughts:
LVDS "Shield" acting as the sole return path for the digital circuit is not good. Add reference ground conductor to cable.
Outer most shield should be tied to the reference ground rather than this capacitor to earth and connected at both ends.
What say you?
Side A:
Voltage Reg
Reference Ground
LVDS receiver
Outer most shield tied to earth through safety capacitors
LVDS lines shield (within the outer most shield) tied to Reference ground
Side B:
Digital circuitry
LVDS transmitter
Reference ground brought to this circuit by means of the LVDS shield
Outer most shield floating (no connection)
Cable:
"Safety Cap" shield encloses:
- Low Speed IO
- VCC
- Reference Grounded LVDS shield which encloses:
- LVDS twisted pair
My thoughts:
LVDS "Shield" acting as the sole return path for the digital circuit is not good. Add reference ground conductor to cable.
Outer most shield should be tied to the reference ground rather than this capacitor to earth and connected at both ends.
What say you?
