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PCB Design

A

Assad

Jan 1, 1970
0
Hi,

I am trying to develop an Embedded board which comprises an Atmega
128L microcontroller and a CHIPCON2420 (RF section) using ORCAD. The
design requires the two sections to have seperate power and ground
planes. i.e, the Microcontroller(ATmega 128L) has its own power and
ground planes which is independent of the power and ground planes of
the CHIPCON2420(RF section). The board is supposed to have 4 layers
only. I would like to know if there is any specfic technique by which
this 4 layer PCB design is handled. I would greatly appreciate if any
of you could help me in this regard.

Regards,
Assad Ansari
 
J

Jeroen

Jan 1, 1970
0
Assad said:
Hi,

I am trying to develop an Embedded board which comprises an Atmega
128L microcontroller and a CHIPCON2420 (RF section) using ORCAD. The
design requires the two sections to have seperate power and ground
planes. i.e, the Microcontroller(ATmega 128L) has its own power and
ground planes which is independent of the power and ground planes of
the CHIPCON2420(RF section). The board is supposed to have 4 layers
only. I would like to know if there is any specfic technique by which
this 4 layer PCB design is handled. I would greatly appreciate if any
of you could help me in this regard.

Regards,
Assad Ansari

A plane layer need not be dedicated to a single ground or power. You can
divide it up in to multiple smaller planes.

Jeroen
 
J

Joerg

Jan 1, 1970
0
Hi Assad,

Separating ground planes can lead to EMI and other problems. Why do they
have to be separated?

I have never had a good experience with split grounds, definitely not
when the digital side contained lots of data buses and modern (fast)
logic chips. Actually I never designed with split grounds but had to
redesign many boards into a common ground architecture after a client
was unable to pass the EMC tests or internal noise had become unmanageable.

Regards, Joerg
 
Q

qrk

Jan 1, 1970
0
Hi,

I am trying to develop an Embedded board which comprises an Atmega
128L microcontroller and a CHIPCON2420 (RF section) using ORCAD. The
design requires the two sections to have seperate power and ground
planes. i.e, the Microcontroller(ATmega 128L) has its own power and
ground planes which is independent of the power and ground planes of
the CHIPCON2420(RF section). The board is supposed to have 4 layers
only. I would like to know if there is any specfic technique by which
this 4 layer PCB design is handled. I would greatly appreciate if any
of you could help me in this regard.

Regards,
Assad Ansari

In Layout help, search for the term "split". They have a section
showing how to create split planes. This might be of interest to you.
This allows you to have multiple planes on the same layer.

Mark
 
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