Attenuator
Input
A1-A10 Attenuator Stages
QS
Attenuator
Output
RS
Q1
A2
Q2
A3
Q3
A4
Q4
A5
Q5
Q6
A7
Q7
A8
Q8
A9
Q9
A10
Q10
VCM
A1
A6
C1
V1
C2
V2
C3
V3
C4
V4
C5
V5
C6
V6
C7
V7
C8
V8
C9
V9
C10
V10
Control
Input
C1-C10 Clipping Amplifiers
0dB
–4.5dB
Attenuation Characteristic of Individual FETs
VCM-VT
0
V1
V2
V3
V4
V5
V6
V7
V8
V9
V10
Characteristic of Attenuator Control Stage Output
Overall Control Characteristics of Attenuator
0dB
–45dB
0.3V
3V
Control Signal
FIGURE 12. Piecewise Approximation to Logarithmic Control Characteristics.
VCA2616, VCA2611
15
SBOS234E
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