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Brittoo
Joined: 24 Jan 2007
Posts: 70
Helped: 11
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 26 Aug 2008 6:25 Do nmos caps require substrates? |
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Hi
In my opinion, the nmos caps do not require the substrate taps.Is that correct? comments welcome.
Regards
Brittoo
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jecyhale
Joined: 19 Feb 2008
Posts: 447
Helped: 46
Location: China
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| 26 Aug 2008 8:32 Re: Do nmos caps require substrates? |
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| Brittoo wrote: |
Hi
In my opinion, the nmos caps do not require the substrate taps.Is that correct? comments welcome.
Regards
Brittoo |
I saw that there is psub pin in TSMC moscap pcell.
I think it is better use a substrate for it.
It can reduce the noise feedthrough more or less.
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Fom
Joined: 10 Mar 2004
Posts: 760
Helped: 56
Location: Taiwan
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| 26 Aug 2008 9:01 Do nmos caps require substrates? |
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1. Pure NMOS: No need because P-substrate is common for all devices and connected to GND.
2. NMOS inside Nwell island: No need because S/D the same type as Nwell.
3. Pure PMOS: Substrate should be connected to S/D because they are different type.
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k_90
Joined: 25 Jan 2006
Posts: 114
Helped: 17
Location: Scotland,GB
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| 26 Aug 2008 13:13 Re: Do nmos caps require substrates? |
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| I agree with jecyhale, always put a substrate around caps and resistors.
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