1 High Speed CMOS IC LAB, POSTECH High Speed CMOS IC LAB, POSTECH Ch 10 전컴569 아날로그 집적회로 Fully differential OP amp 10.2 완전 차동(fully differential) OP amp Differential input, Differential output Easy to cascade OP amps insensitive to supply noise High gain Fully diff OP amp requires CMFB
16
Embed
10.2 완전차동(fully differential) OP ampread.pudn.com/.../ebook/320585/FUlly_differential_OP_amp.pdf · 2007-08-17 · 전컴569 아날로그집적회로 Fully differential OP
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
1High Speed CMOS IC LAB, POSTECHHigh Speed CMOS IC LAB, POSTECH
Ch 10 전컴569 아날로그 집적회로 Fully differential OP amp
10.2 완전 차동(fully differential) OP amp
Differential input, Differential outputEasy to cascade OP ampsinsensitive to supply noiseHigh gain Fully diff OP amp requires CMFB
2High Speed CMOS IC LAB, POSTECHHigh Speed CMOS IC LAB, POSTECH
Ch 10 전컴569 아날로그 집적회로 Fully differential OP amp
10.2.1 NMOS 입력 완전 차동 folded cascode OP ampVDD
VB1
M4M5
M12 M13
M7M6
M8M9
M11M10
M3
M2M1
VB2
CL CL
VB3
VCMFB
VB4
Vi+
Vi-
Vo+
Vo-
VSS
그림 10.2.1 완전 차동(fully differential) folded cascode OP amp 회로
M12, M13 increases slew rate
3High Speed CMOS IC LAB, POSTECHHigh Speed CMOS IC LAB, POSTECH
Ch 10 전컴569 아날로그 집적회로 Fully differential OP amp
10.2.2 Rail-to-rail 완전 차동 folded cascode OP amp (*)
PTHpDDB VVV ∆−−=1
NTHnSSCMFBB VVVV ∆++==4
최소값 : NTHnSS VV ∆⋅++ 2
최대값 : VVV >∆−+ DDPTHnDD o o
VDD
VB1
IB3
VB2
M2pM1p
M1n M2n
VB3
Vi - Vi+
CL
VSS
VB4
VCMFB
Vi - Vi
+
V+
V -
CLIB2
M4M3p
M5
M6 M7
M3n
M8M9
M10 M11
그림10.2.2 Rail-to-rail 완전 차동 folded cascode CMOS OP amp 회로
최소값 : SSNTHpSS VVV <∆+−
최대값 : PTHpDD VV ∆⋅−− 2
4High Speed CMOS IC LAB, POSTECHHigh Speed CMOS IC LAB, POSTECH
Ch 10 전컴569 아날로그 집적회로 Fully differential OP amp
표 10.2.1 그림 10.2.2에 보인 rail-to-rail 완전 차동 folded cascode OP amp 회로의 동작 특성
( , )NTHnSSsn VVV ∆⋅++= 2 PTHpDDsp VVV ∆⋅−−= 2
vdA
snSS VV ~ opm Rg ⋅1
spsn VV ~ opmnm Rgg ⋅+ )( 11
DDsp VV ~ onm Rg ⋅1offon
onon
onoff
저주파 차동모드
전압이득
PMOS차동증폭단
NMOS차동증폭단
공통모드입력전압범위
VDD
VB1
IB3
VB2
M2pM1p
M1n M2n
VB3
Vi - Vi
+CL
VSS
VB4
VCMFB
Vi - Vi
+
Vo+ Vo
-
CLIB2
M4 M3pM5
M6 M7
M3n
M8 M9
M10 M11
5High Speed CMOS IC LAB, POSTECHHigh Speed CMOS IC LAB, POSTECH