Download presentation
Presentation is loading. Please wait.
Published byYandi Halim Modified over 6 years ago
1
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
2
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
3
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+
4
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
5
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
6
VDD VDD Vo Vo Folded cascode
7
VDD Vin CL Vbb flip up-down for I sources VDD M1 Vin CL M2 Vbb connecting n-D to p-S
8
VDD VDD folded cascode amp Vbb Vin+ Vin- CL
9
D1 connects to G2, two stages
VDD VDD VDD VDD two stage CS amplifier CS amplifier with a source follower buffer
10
VDD VDD VDD Vx Vx Same as above, only T2 is pMOS Connecting S1 to D2 makes ro really small buffer or output stage
11
Frequency dependent analysis
By including the effects of capacitors and by using s-domain impedances
12
MOST model: saturation
Chapter 4 Figure 11 Cgs 2/3 CoxWL, Cgd = CoxWLov= Cgd0W Cdb = CjAD+CjswPD, Csb tricky, mostly short
13
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.
14
1:M Voutmax Vin I1Q=I2Q= Pcs= Ptot= Voutmin
15
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
16
Av(0) = p1 = z1 = BW = |p1| = GBW = Av(0)* BW= SR = max dvout/dt =
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.