is there a difference between gnd and gnd plane

[amateur_24]

Hi
I thought the gnd plane and gnd of the power supply is different. The gnd plane is a solid conductive surface used to reduce electricial interferance. So I might connect the outer pins of a usb port to it.

The ground of a power supply is the negative terminal.
Am I not correct?

 

[Reloadron]

Hi
I thought the gnd plane and gnd of the power supply is different. The gnd plane is a solid conductive surface used to reduce electricial interferance. So I might connect the outer pins of a usb port to it.

The ground of a power supply is the negative terminal.
Am I not correct?

Stolen from the Wiki...

A ground plane in PCB assembly is a layer of copper that appears to most signals as an infinite ground potential. This helps reduce noise and helps ensure that all integrated circuits within a system compare different signals' voltages to the same reference potential.

It also serves to make the circuit design easier, allowing the designer to ground anything without having to run multiple tracks; the component needing grounding is routed directly to the ground plane on another layer.

Ground planes can also be placed on adjacent layers to power planes creating a large parallel plate capacitor that helps filter the power supply.

Ground planes are sometimes split and then connected by a thin trace. This allows the separation of analog and digital sections of a board or the inputs and outputs of amplifiers. The thin trace has low enough impedance to keep the two sides very close to the same potential while keeping the ground currents of one side from impacting the other.

That discounts Ground Plane as it can pertain to antenna theory.

A ground plane can also be thought of as a common ground potential tie point.

So I might connect the outer pins of a usb port to it.

No. A USB 2.0 connector uses 4 pins. The two center pins are data. The outer pins are +5 volts (pin 1) and ground (pin 4). Depending on circuit configuration pin 4 may be connected to the ground plane or common but not pin 1 which is 5 volts.

Does that help?

Ron

 

[KeepItSimpleStupid]

Negative. No. Suppose the supply is -48V or +-12?

Ground planes generally reduce stray capacitance. A 4 layer board might have component, foil, ground and V which makes it easier to route.

Circuits can have Analog GND, Digital GND, Protective GND(Earth)
They are usually connected together at one point. AGND is quiet. DGND is noisy and PG protects the operator against shock.

 

[crutschow]

A Gnd Plane is Gnd. There is no difference in designation between Gnd Plane and Gnd. It is simply a physical method of providing the Gnd connections. It is the negative supply connection if you have a single positive supply.

The main purpose of a Gnd Plane it to reduce ground inductance which can cause noise in high frequency circuits. It also minimizes reflection noise in high frequency signal traces.

 

[Ian Rogers]

Is the confusion Gnd vs 0v? or digital Gnd vs analogue Gnd? as these do differ. In electronics its best to keep them apart until they can connect with a larger Ground area so as little interference cross talk as possible.

Ian