Sujet: High voltage isolation

High voltage isolation
Hello,
What are the theoretical and practical limits for
voltage differential between tracks on one side of
a board, or on opposite sides of a board (both
double-sided and 4-layer)? Any differences for
buried vias, or where a through-hole penetrates an
earth plane, or where a surface mount component
is placed opposite an earth or power plane? What
about 2 earth planes 1000V apart inside a 4-layer
sandwhich?

I'm planning a circuit with a 1000V DC-DC converter,
a high-isolation +-15V DC-DC converter to produce
component supply voltages on the high side, very
high input isolation electrometer amplifiers and
A/D-converters on the high side, and optically
isolated I2C data bus. Also need to know the
isolation in ohms between opposing copper planes
in a 4-layer sandwhich and in a normal double-sided
board. Leakage currents are never "zero", and are
significant for me however small they may be!

Best regards
Terje
13/04/2002 09:22:40
Terje Krognes
Re: High voltage isolation
: Hello,
: What are the theoretical and practical limits for
: voltage differential between tracks on one side of
: a board, or on opposite sides of a board (both
: double-sided and 4-layer)? Any differences for
: buried vias, or where a through-hole penetrates an
: earth plane, or where a surface mount component
: is placed opposite an earth or power plane? What
: about 2 earth planes 1000V apart inside a 4-layer
: sandwhich?
:
: I'm planning a circuit with a 1000V DC-DC converter,
: a high-isolation +-15V DC-DC converter to produce
: component supply voltages on the high side, very
: high input isolation electrometer amplifiers and
: A/D-converters on the high side, and optically
: isolated I2C data bus. Also need to know the
: isolation in ohms between opposing copper planes
: in a 4-layer sandwhich and in a normal double-sided
: board. Leakage currents are never "zero", and are
: significant for me however small they may be!
:
: Best regards
: Terje

Hi Terje,

Thanks for asking PCB-FAQ.COM the latest community in PCB world.
O.K. the first part of your question depends entirely on the material and thickness of the PCB. When you are laying out your design, we recommend that you ask your manufacturer for the type of material he is using. Then you can work out what thickness you require. With Multi layer what thickness of prepreg etc etc.
The second part is purely an electronics question, and unfortunately we don`t have any body here that specialises in High Voltage Electronic circuits, but the isolation in ohms can be worked out just like a coaxial impedence. Z = L/C.
If there is anybody out there who may be able to help Terje further, please do not hesitate to make your entry.
Thank you all
Your Beta LAYOUT team


15/04/2002 19:48:34
Beta LAYOUT GmbH Service Team
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