| Author |
Message |
Jim Thompson
Guest
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 Posted:
Sat Feb 05, 2005 12:41 am Post subject:
Modeling Series R in an MOS (Active Device) Capacitor ?? |
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I'm trying to come up with a model of the series resistance of a
capacitor formed using gate-channel capacitance and with drain-source
merged.
Refer to....
http://www.analog-innovations.com/SED/MOS-CAP-Series-R.pdf
(I'm not very good at conformal mapping of rectangular objects :-)
Ideas?
Thanks in advance!
...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice:(480)460-2350 | |
| E-mail Address at Website Fax:(480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |
I love to cook with wine. Sometimes I even put it in the food.
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John Larkin
Guest
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| Posted:
Sat Feb 05, 2005 1:05 am Post subject:
Re: Modeling Series R in an MOS (Active Device) Capacitor ?? |
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On Fri, 04 Feb 2005 11:41:06 -0700, Jim Thompson
<thegreatone@example.com> wrote:
| Quote: | I'm trying to come up with a model of the series resistance of a
capacitor formed using gate-channel capacitance and with drain-source
merged.
|
That's cheating. Not nice.
Where on the sheet do you make the connection? The location and
geometry of the connection matter.
Clearly a single resistance will be an imperfect model. Capacitance
near the contact is nearly pure, and capacitance farther away sees
more series R. It's one of those nasty diffusion things.
John |
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Jim Thompson
Guest
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| Posted:
Sat Feb 05, 2005 1:09 am Post subject:
Re: Modeling Series R in an MOS (Active Device) Capacitor ?? |
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On Fri, 04 Feb 2005 11:05:52 -0800, John Larkin
<jjlarkin@highSNIPlandTHIStechPLEASEnology.com> wrote:
| Quote: | On Fri, 04 Feb 2005 11:41:06 -0700, Jim Thompson
thegreatone@example.com> wrote:
I'm trying to come up with a model of the series resistance of a
capacitor formed using gate-channel capacitance and with drain-source
merged.
That's cheating. Not nice.
Refer to....
http://www.analog-innovations.com/SED/MOS-CAP-Series-R.pdf
(I'm not very good at conformal mapping of rectangular objects :-)
Ideas?
Where on the sheet do you make the connection? The location and
geometry of the connection matter.
|
Connections: Merged Drain-Source is one connection, Gate Plate is the
other.
| Quote: |
Clearly a single resistance will be an imperfect model. Capacitance
near the contact is nearly pure, and capacitance farther away sees
more series R. It's one of those nasty diffusion things.
John
|
A two-dimensionsal ladder would be OK as a model.
Clearly I'm asking because it's not easy ;-)
I prefer "fingered" structures myself (which model easily, since
they're one-dimensional), but a client is using this without a clue of
the series R effect :-(
...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice:(480)460-2350 | |
| E-mail Address at Website Fax:(480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |
I love to cook with wine. Sometimes I even put it in the food.
|
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| Back to top |
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Jim Thompson
Guest
|
| Posted:
Sat Feb 05, 2005 2:42 am Post subject:
Re: Modeling Series R in an MOS (Active Device) Capacitor ?? |
|
|
On Fri, 04 Feb 2005 11:41:06 -0700, Jim Thompson
<thegreatone@example.com> wrote:
| Quote: | I'm trying to come up with a model of the series resistance of a
capacitor formed using gate-channel capacitance and with drain-source
merged.
Refer to....
http://www.analog-innovations.com/SED/MOS-CAP-Series-R.pdf
(I'm not very good at conformal mapping of rectangular objects :-)
Ideas?
Thanks in advance!
...Jim Thompson
|
Square (most common case, L=W) is fine, if it helps the modeling.
...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice:(480)460-2350 | |
| E-mail Address at Website Fax:(480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |
I love to cook with wine. Sometimes I even put it in the food. |
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