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twolevel2002
Joined: 08 Jan 2005
Posts: 32
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 08 Jan 2005 19:03 HIGH VOLTAGE PROCESS |
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Dear all :
I am using a high voltage process model to do some design.
I have a problem as below :
Due to the high voltage process can't drive much current , the mosfet just only has 100~200 nA but it is still in saturation region.
But somebody knows what the practial measurement is ?
Is it possible to have only 100~200 nA and work correctly in a real IC ?
If not , how much current is appropriate and reasonable ?
My process is UMC 0.6u 18v.
TKS
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electronrancher
Joined: 24 Mar 2002
Posts: 474
Helped: 34
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| 10 Jan 2005 23:23 HIGH VOLTAGE PROCESS |
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That sounds too weak - I think your transistor is sized wrong. First, 0.6um can't hold up to 18v, it would need to be 2-4um meaning that you should be using sizes nearer to 20/2 rather than 6/0.6. Are these mosfets DMOS or standard CMOS?
Can you PM me - I am interested in this process, I would like to take a look. I can help debug your mosfet troubles as a return favor.
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twolevel2002
Joined: 08 Jan 2005
Posts: 32
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| 11 Jan 2005 16:30 HIGH VOLTAGE PROCESS |
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yes , it's right.
Although this is a 0.6um process , the high voltage device must have 3um length at least.
But the process file is confidential, I can't share it to you,sorry.
I just want to know if the simulation current in saturation region is 100-200nA, how much current will be the real current ?
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mists
Joined: 14 May 2002
Posts: 380
Helped: 33
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| 12 Jan 2005 5:05 HIGH VOLTAGE PROCESS |
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| i think the 100-200nA is too small, and this value will be much difference in different PVT corner, so it is hard to designcircuit.
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okguy
Joined: 01 Mar 2002
Posts: 560
Helped: 6
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| 12 Jan 2005 16:50 Re: HIGH VOLTAGE PROCESS |
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| Are you sure that your HV models are accurate in that region ... suggest to check with UMC.
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alanbrooke
Joined: 13 Feb 2004
Posts: 40
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| 13 Jan 2005 3:36 Re: HIGH VOLTAGE PROCESS |
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Wah! only 200nA, So small,
maybe I think it is the leakage current in HV process.
Can you double check it?
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Colbhaidh
Joined: 10 Aug 2004
Posts: 151
Helped: 16
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| 17 Jan 2005 11:44 Re: HIGH VOLTAGE PROCESS |
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I have worked on a high voltage 20V nmos transistor (not UMC) and the Idsat was around uA. What you are seeing must be Idss (sub threshold leakage current -although it is high) or weak inversion current.
Remember the Vt of this device will be about 1.0V or more.
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