1. vs vb cc VDD VDD VDD M9 M12 M11 vo Iref M1 M2 vin vin+= voQ CL vf=vinRc R M5 M6
M10 M7 M8
vin2

2. From last time:
Some book talk about choosing Rc to cancel p2 and achieve first order like behavior. Not possible.

3. If we let Rc = a/gm10
If appropriate Cf is used in parallel to Rf, b is real is = Ri/(Ri+Rf). Then at wt, we have:

6. Strategy:
Use an appropriate C in parallel with Rf so that b is independent of s
Use binary search between C1 and CL to find a good Cc. Start with Cc=(C1+CL)/2
Sweep Rc to find Rc to maximize PM
If PM about right, stop.
If PM too large, reduce Cc, else increase Cc, but go back to 2 to use binary search for new Cc

7. Cascoded current mirrors:
Ro = rds2 * A4
VDD
Large, good! Io
Iin
Vomin = Veff2+Vt4+Veff4 Vo M3 M4
Too high M1 M2

8. Wide swing cascoded current mirrors:
Ro = rds2 * A4
VDD
Large, good! Io
Vomin = Vg4 – Vt4
= Vg2 + IR – Vt4
= Veff + Vt2 + IR – Vt4
= Veff + IR
Vds2 = IR > Veff
Vomin = 2Veff R Vo M4 M3 M1 M2

9. Regulated cascode:
Suppose test signal it.
vd2 = vs1 = it *rds2, vg1 = -Avd2.
vgs1=(1+A)vd2
id1=gm1(1+A)vd2 +gs1vd2
vt= it *rds2 + it *rds1
+ id1 *rds1
Rout= rds2 + rds1 + gs1rds1rds2
+ gm1(1+A)rds1rds2
 Agm1rds1rds2

10. A(s)=gm5gm7/{gm6(gds7+gds8+sCdb7+sCdb8+sCgs4)}
VDD
VDD
VDD
4 transistor and 1 resistor Io M6 M7 R Vo M4 M3 M5 M1 M2 M8

11. A(s)={gm7/(1+gm7(1/gm1+1/gm2}/ (gds7+gds8+sCdb7+sCdb8+sCgs4)
VDD
Only 2 transistors Io
Gain reduced by about 3X Vo M7 M3 M4 M1 M2 M8

12. Folded cascode For single stage, For two stage,
Telescopic cascode has OSR limited by Vic
Folding makes OSR independent of Vic, and always large
For two stage,
Both tele and folded have large OSR independent of Vic
Folded has less stacking
Folded allows better ro control
Folded consumes more power

14. Self biasing vb vb cc VDD VDD VDD VDD M13 M3 M4 M12 vo CL M5 M6 Iref RRc R
vin M1
vin+ M2 M7 M8
M11
M14 M9
M10
vin2

15. Current mirror amplifier
A(s)=Kgm1/(Go+sCo)

16. Self biasing with resistors
Same gain expression

17. Non cascoded
Same gain expression, but Go is just gds8+gds14