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problem with current mirror (Read 2697 times)
icekalt
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problem with current mirror
Jul 24th, 2009, 7:34am  
Hello,

When i simulated the circuit below, the drain current of transistor M5 is not equal to 100uA. What is the problem here?

thx
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raja.cedt
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Re: problem with current mirror
Reply #1 - Jul 24th, 2009, 8:07am  
hi,
  please check vds of M5..i think the problem is because of less common mode voltage.if you have less vds then please increase input common mode voltage.

Thanks,
Rajasekhar.
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icekalt
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Re: problem with current mirror
Reply #2 - Jul 24th, 2009, 8:35am  
raja.cedt wrote on Jul 24th, 2009, 8:07am:
hi,
  please check vds of M5..i think the problem is because of less common mode voltage.if you have less vds then please increase input common mode voltage.

Thanks,
Rajasekhar.


hello,

Vds is 1.17687nV.
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boe
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Re: problem with current mirror
Reply #3 - Jul 24th, 2009, 11:08am  
icekalt wrote on Jul 24th, 2009, 8:35am:
hello,

Vds is 1.17687nV.

Then the transistor is not in saturation and therefor, will not act as current source.
BOE
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raja.cedt
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Re: problem with current mirror
Reply #4 - Jul 25th, 2009, 1:08am  
hi,
   so please increase vds of the tail transistor (just increase the common mode voltage)

Thanks,
rajasekhar.
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