When the length of the signal line is larger than 300mm, it should be taken parallel to the ground.
Make sure the loop between the signal line and a corresponding loop area as small as possible. For every few centimeters long signal line will have to swap the location of the signal line and ground to reduce the loop area.
The plurality of receiving circuit’s center position of the drive signal from the network. Make sure the loop area between power and ground is as small as possible, placing a high frequency integrated printed circuit chip capacitor near the power pin of each place. Each connector is placed at a distance within a range of 80mm from high-frequency bypass capacitor. Wherever possible, fill the unused areas with ground.
Ensure that filled arbitrarily large area (greater than approximately 25mm × 6mm) of the two opposite end positions to be connected to the ground. Length of both the sides exceeds 8mm, use a narrow line of the opening further connecting the power or ground plane. Reset line interrupt signal line or edge-triggered signal line cannot be arranged in a place near the edge of the custom cicuit board.
The mounting holes with the circuit commons are connected together or isolate them.
(1) Metal stent and metal shielding methods must be used together or enclosure, by use of a zero-ohm resistor connected.
(2) to determine the size of the mounting holes, achieve reliable installation of metal or plastic stents, on the top and bottom mounting holes to be used large pad cannot be used on the solder resist layer pads, and make sure the bottom of the pad without using wave soldering processes welding.
Protected and unprotected signal lines are arranged in parallel. Pay special attention to reset, interrupt, and control signal wiring lines for:
(1) For a high-frequency filter.
(2) Away from the input and output circuits.
(3) Away from the edge of the board.
Bare PCB board should be inserted into the chassis, do not install or open position inside seams.
Note that under the bead wire, and between the pads may be exposed to magnetic beads signal lines. Some beads quite good conductive properties, may have unintended conductive path.
If a chassis or PCB motherboard to be built a few circuit boards, will be the most sensitive to static electricity board in the middle.
