M2 M1 Vbb Vin CL M4 M3 Vyy Vxx VDD VDD Vo<Vxx+|Vt3| flip up-down for source Rb M2 Vbb CL M1 Vin connecting D1 to S2 cascoding Vo> Vbb-Vt2 ro = rop||ron, Av=-gm1*ro

VDD VDD flip left-right to get this differential telescopic cascoded amplifier M7 M5 Vyy Vxx Vo<Vxx+|Vt3| M8 M6 vo- vo+ CL M3 M4 Vbb CL M1 M2 vin+ vin- Vs Vo> Vbb-Vt2 Tail current to change gnd to virtual gnd

Let vin+ = Vic + ½ vid, vin- = Vic - ½ vid The cross source: Vs = Vic – VGS1Q. Left half circuit same as two slides back, but with vin = ½ vid. So vo- = - gm1ro-(½ vid), where ro- = ro5,7||ro1,3. Similarly, vo+ = - gm1ro+(-½ vid), where ro+ = ro6,8||ro2,4. Hence: vod = gm1rovid Av = vod/vid = gm1ro where ro = ro- = ro+

ICMR M3 M4 Vbb What is Vicmax? VD1 = Vbb-Vt3-Veff3 For M1 in saturation, need VD1>VG1Q–Vt1 =Vic–Vt1. So, Vic<Vbb-Vt3-Veff3+Vt1 Vicmax=Vbb-Veff3 What is Vicmin? Vs>Veff9 for M9 in saturation. Vic>Veff9+Veff1+Vt1 Vicmin=Veff9+Veff1+Vt1 M1 M2 vin+ vin- Is M1 M2 vin+ vin- M9

VDD VDD Diode connection to turn diff out to single-ended output  M7 M5 M8 Vo<VG6+|Vt6| M6 vo Same ICMR. But Vo range is different. VG6=VDD-2Vtp-2Veff M3 M4 CL Vbb M1 M2 vin+ vin- Vo>Vbb-Vt2 Same Av, ro

VDD VDD Vo Vo Folded cascode

VDD Vin CL Vbb flip up-down for I sources VDD M1 Vin CL M2 Vbb connecting n-D to p-S

VDD VDD folded cascode amp Vbb Vin+ Vin- CL

D1 connects to G2, two stages VDD VDD VDD VDD two stage CS amplifier CS amplifier with a source follower buffer

VDD VDD VDD Vx Vx Same as above, only T2 is pMOS Connecting S1 to D2 makes ro really small buffer or output stage

Frequency dependent analysis By including the effects of capacitors and by using s-domain impedances

MOST model: saturation Chapter 4 Figure 11 Cgs  2/3 CoxWL, Cgd = CoxWLov= Cgd0W Cdb = CjAD+CjswPD, Csb tricky, mostly short

Non-symmetric operation  Csb > Cdb Chapter 4 Figure 12 Non-symmetric operation  Csb > Cdb If S-B together, Csb is shorted. Easy for PMOS, but for NMOS, true only if S=gnd.

1:M Voutmax Vin I1Q=I2Q= Pcs= Ptot= Voutmin

For Zo, set vin=0; Yo=gds1+gds2+s(C2+Cgd1) KCL at vout: gm1vin-sCgd1 +Yovout=0 Av(s) = (sCgd1-gm1)/Yo C2=CL+Cdb1 +Cdb2 1/R2= gds1+gds2

Av(0) = p1 = z1 = BW = |p1| = GBW = Av(0)* BW= SR = max dvout/dt =