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Simulators >> Circuit Simulators >> how to evaluate the PSRR for a current output signal?
https://designers-guide.org/forum/YaBB.pl?num=1253637820

Message started by subgold on Sep 22^nd, 2009, 9:43am

Title: how to evaluate the PSRR for a current output signal?
Post by subgold on Sep 22^nd, 2009, 9:43am

i have a bias current generator. the output current is copied to many branches via current mirrors, and will be used through different resistors and diode connected transistors.

now i want to check the influence of the supply voltage fluctuation on the generated current. i just use a 'xf' simulation to check it. however, different PSRR values appear at different current branches (i already normalize the value to the unit current), which implies that the PSRR of this current is also depending on the property of the load. is this true? or are there any other more reasonable way to check the PSRR of this current output?

thanks.

Title: Re: how to evaluate the PSRR for a current output signal?
Post by raja.cedt on Sep 22^nd, 2009, 9:36pm

hi,
psrr at every node in case current mirror is depends on the size of mosfet, if every branch current is same then psrr should be same...

Thanks,
Rajasekhar.

Title: Re: how to evaluate the PSRR for a current output signal?
Post by subgold on Sep 23^rd, 2009, 5:24am

raja.cedt wrote on Sep 22^nd, 2009, 9:36pm:

hi,
psrr at every node in case current mirror is depends on the size of mosfet, if every branch current is same then psrr should be same...

Thanks,
Rajasekhar.

hi,

which mosfet are you referring to? the mirror transistor or the diode-connected transistor? and actually in my case neither of those is identical in every branch.

thanks.