Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.
Phase magin is necessary. Gain is important to ensure that the voltages of the positive and negitive input terminals are equal, too. and other PSRR is also important for the bandgap voltage undepending on the supply voltage, i think.
So we can get a conclusion of 'gm2=gm1' if the two branches current are equal just as jordan76 said , and gm*(R1+1/gm2) > gm*1/gm1 must be right with the matched size of mirror PMOS. An overall negative feedback can be ensured.
What's the exact parameter for the bipolar transistor? gm=Ic/Vt ? Isn't undepending on the Is? here Is is the saturation current, and Is2=nIs1 since the area ratio of them is n:1.
The negative feedback factor is Betan=gm*(R1+1/gm2),here gm is the transconductance of the PMOS and gm2 is the transconductance of the transistor with area of nA.
The positive feedback factor is Betap=gm*1/gm1 , here gm1 is the transconductance of the transistor with area of A.
Are the factors...
In the circuit of bandgap , the feedback signal produced by the op amp returns to both of its inputs. so how to ensure that the negative feedback factor is more than the positive feedback factor ? Isn't necessary to ensure an overall negative feedback? or the bandgap circuit must be negative...
pole/zero analysis?
usually we can find the node with the largest capacitor and impedence to decide which node is the position causing the dominate pole and the second non dominant pole. At the output teminal , there should be the dominate pole or the second non dominant pole. and the node with...
R=1/gm51 to cancell the Influence of the zero point and C depends on the load capacitor and the ratio of the first stage amplifier gain and the second stage amplifer.usually we take the factor of 2~3 .
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.
