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A plane has problems. Example

^{simulate this circuit – Schematic created using CircuitLab}

When you expect certain (hopefully nearby) nodes of the Ground Plane to have ZERO volts between those two nodes, that will not happen. Slits can be your friend, to reduce the interfering currents passing along the path between your two sensitive nodes.

^{simulate this circuit}

Take a copy of the schematic, printed out, and draw ALL the ground currents. Label their values and frequencies and edge-rates. (inductance may matter).

Now start planning how to keep the noise currents away from the GROUND nodes of your sensitive (feedback voltage dividers) circuits.

Note how WIDE slits provide more attenuation of bothersome currents.

My thinking on planes, tho I've done many fast circuits on planes at moderate fidelity, concerned the need for extreme fidelity for audio/music signals and for low-frequency 20/24 bit measurements. Thus LOW FREQUENCY thinking.

[oh Magnetic and Electric fields also matter]

A plane has problems. Example

^{simulate this circuit – Schematic created using CircuitLab}

When you expect certain (hopefully nearby) nodes of the Ground Plane to have ZERO volts between those two nodes, that will not happen. Slits can be your friend, to reduce the interfering currents passing along the path between your two sensitive nodes.

^{simulate this circuit}

Take a copy of the schematic, printed out, and draw ALL the ground currents. Label their values and frequencies and edge-rates. (inductance may matter).

Now start planning how to keep the noise currents away from the GROUND nodes of your sensitive (feedback voltage dividers) circuits.

Note how WIDE slits provide more attenuation of bothersome currents.

My thinking on planes, tho I've done many fast circuits on planes at moderate fidelity, concerned the need for extreme fidelity for audio/music signals and for low-frequency 20/24 bit measurements. Thus LOW FREQUENCY thinking.

[oh Magnetic and Electric fields also matter]

A plane has problems. Example

^{simulate this circuit – Schematic created using CircuitLab}

When you expect certain (hopefully nearby) nodes of the Ground Plane to have ZERO volts between those two nodes, that will not happen. Slits can be your friend, to reduce the interfering currents passing along the path between your two sensitive nodes.

^{simulate this circuit}

Take a copy of the schematic, printed out, and draw ALL the ground currents. Label their values and frequencies and edge-rates. (inductance may matter).

Now start planning how to keep the noise currents away from the GROUND nodes of your sensitive (feedback voltage dividers) circuits.

Note how WIDE slits provide more attenuation of bothersome currents.

[oh Magnetic and Electric fields also matter]

A plane has problems. Example

^{simulate this circuit – Schematic created using CircuitLab}

When you expect certain (hopefully nearby) nodes of the Ground Plane to have ZERO volts between those two nodes, that will not happen. Slits can be your friend, to reduce the interfering currents passing along the path between your two sensitive nodes.

^{simulate this circuit}

Take a copy of the schematic, printed out, and draw ALL the ground currents. Label their values and frequencies and edge-rates. (inductance may matter).

Now start planning how to keep the noise currents away from the GROUND nodes of your sensitive (feedback voltage dividers) circuits.

Note how WIDE slits provide more attenuation of bothersome currents.

My thinking on planes, tho I've done many fast circuits on planes at moderate fidelity, concerned the need for extreme fidelity for audio/music signals and for low-frequency 20/24 bit measurements. Thus LOW FREQUENCY thinking.

[oh Magnetic and Electric fields also matter]

A plane has problems. Example

^{simulate this circuit – Schematic created using CircuitLab}

When you expect certain (hopefully nearby) nodes of the Ground Plane to have ZERO volts between those two nodes, that will not happen. Slits can be your friend, to prevent the interfering currents passing along the path between your two sensitive nodes.

^{simulate this circuit}

Take a copy of the schematic, printed out, and draw ALL the ground currents. Label their values and frequencies and edge-rates. (inductance may matter).

Now start planning how to keep the noise currents away from the GROUND nodes of your sensitive (feedback voltage dividers) circuits.

[oh Magnetic and Electric fields also matter]

A plane has problems. Example

^{simulate this circuit – Schematic created using CircuitLab}

When you expect certain (hopefully nearby) nodes of the Ground Plane to have ZERO volts between those two nodes, that will not happen. Slits can be your friend, to reduce the interfering currents passing along the path between your two sensitive nodes.

^{simulate this circuit}

Take a copy of the schematic, printed out, and draw ALL the ground currents. Label their values and frequencies and edge-rates. (inductance may matter).

Now start planning how to keep the noise currents away from the GROUND nodes of your sensitive (feedback voltage dividers) circuits.

Note how WIDE slits provide more attenuation of bothersome currents.

[oh Magnetic and Electric fields also matter]