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Hi all,
I'm considering AC response of the uncompensated LDO. You can see this picture.
Can you show me that how many poles, zeros are in circuit? And formula to calculate them?
Thanks
Thank araya.jagadeesh!
I use the single ended 2 stages opamp in my LDO. After I run DC simulation, I have parameters:
Gm1=0.0269; R1=1329K;C1=18.2(fF); Mosfet MP has: Gm=384.1u; Rds=685.7K; Cgs=131.6(fF); Cgd=48.7(fF). So, applying your formula, pole at P1 is 9.23 Khz. It's very different from simulation result.
What's wrong?
I hope to receive your answer!
Hello arya.jagadeesh,
I think out pole is calculated: 1/[Cout*((Rf1+Rf2)//Rds)]. Cout=15pF; Rf1=23.5K; Rf2=49.3K; Rds=943K. So, output pole is 156.7Mhz.
Is this true?
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