Source Termination Method on Infometer Touch PCB Reverse Engineering
The source termination method on Infometer Touch PCB Reverse Engineering, absorbs the reflected waveform with an impedance equal to that of the transmission line. This requires about 39 Ù in series with the internal output impedance of the driver, which is generally about 10 Ù.
This technique requires that the end of the transmission line be terminated in an open circuit, therefore no additional fanout is allowed. The source termination method adds no additional quiescent power dissipation to the circuit.
Below Figure shows a method for distributing a high speed clock to several devices. The problem with this approach is that there is a small amount of time skew between the clocks because of the propagation delay of the microstrip line (approximately 1 ns /7″). This time skew may be critical in some applications. It is important to keep the stub length to each device less than 0.5″ in order to prevent mismatches along the transmission line.
Clock Distribution Using End-of-Line Termination on PCB Reverse Engineering
The clock distribution method shown in below Figure minimizes the clock skew to the receiving devices by using source terminations and making certain the length of each microstrip line is equal. There is no extra quiescent power dissipation as would be the case using end termination resistors.
Preferred Method of Clock Distribution Using Source Terminated Transmission Lines
