Date post: | 21-Dec-2015 |
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spatial bandpass filter
Which is commonly usedin computer vision to findvisual "edges" to determinethe shape of objects.
Vout
IphotoVp
If the loop is closed, we have our familiar circuit which has Vout =
2ln( ) ln( )
T bias T photo
o o
V I V IVout
K I K I
1TVout V
Iphoto K Iphoto
Because the ac gain of the amplifier is very high, in practice, itis better to limit the gain using a capacitor divider.
Vf
Vout
Iphoto
High gain inverting amp
Vp
C1
R
C2
1 2 1
2
TVout V C C
Iphoto K Iphoto C
Since Vout now does the same job of feedback through the capacitor divider,