3.7.5.13 Galvanic Isolation
Galvanic isolations in the signal path can be achieved by transformers, optocouplers, or specialized
ICs. Especially in harsh environments, galvanic isolation is a preferred method for isolating power
domains of different devices. The so-called magnetics inside the Ethernet connector is also a
galvanic isolator and prevents backfeeding over the Ethernet cable. Galvanic isolators are also
preferred way for protecting different power domains of CAN interfaces.
Figure 54: Galvanic isolation between input and output
3.7.5.14 Reverse Current Protection in IO Rail
By placing a diode in the IO rail's power supply, reverse current to other IO rail devices can be
prevented. For example, this is a preferred solution for protecting the HDMI CEC signal from
backfeeding to the 3.3V rail. However, it is not always a feasible solution due to the forward
voltage drop on the IO voltage rail.
Figure 55: Reverse current protection diode
To Next Page
Loading...