§ 3-3 Voltage follower（跟随器） (or isolator隔离器 )
The voltage follower is a circuit in which the output is
identical to the input.
12 ?? ?
1,
,
1
2
12
21
???
??
?
?
??
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or
xx
The controlled-source representation of the voltage follower:
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?
1? ?
?
?
?
2?1?
x?
?
?
1?
??
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?
?
2?
?
?
?
The application of the voltage follower
oR RR
R
L
????
21
2
12 ????
1
21
2
1
21
2
1
????
??
?
?
??
?
?
o
L
L
R
o
RRR
RR
RR
R
L //
//
'
Cascade(级联 ） of OP-AMP circuits
12 2?? ?
?
??
??
?
1
23
4
2
?
??