Analog Devices EVAL-AD5161DBZ User Manual page 5

EVAL-AD5161DBZ User Guide
Signal Amplifier
The RDAC can be operated as an inverting or noninverting
signal amplifier and can support linear or pseudologarithmic
gain. Table 6 shows the available configurations.
The noninverting amplifier with linear gain is shown in Figure 4,
and the gain is defined in Equation 3.
R
= 1 + WB
G
R38
where R is the resistance between the W and B terminals.
WB
V
IN
W2
Figure 4. Noninverting Amplifier with Linear Gain
The noninverting amplifier with pseudologarithmic gain is
shown in Figure 5, and the gain is defined in Equation 4.
R
= 1 +
WB
G
R
AW
where:
R is the resistance between the W and B terminals.
WB
R is the resistance between the A and W terminals.
AW
Table 6. Amplifier Selection Link Settings
Amplifier
Noninverting
Inverting
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R41
1.7kΩ
VOUT2
R38
2.7kΩ
C1
10nF
B2
W B R42
RDAC
Gain
Linear
Pseudologarithmic
Linear
R43
(3)
Figure 5. Noninverting Amplifier with Pseudologarithmic Gain
R43 and R42 can be used to set the maximum and minimum
gain limits.
The inverting amplifier with linear gain is shown in Figure 6,
and the gain is defined in Equation 5.
R
= − WB
G
R38
where R is the resistor between the W and B terminals.
WB
Note that the input signal, V
V
(4)
NOTES
1. THE INPUT SIGNAL, V
Figure 6. Inverting Amplifier with Linear Gain
Link Settings
Daughter Board
P5: A2 position,
P6: W2 position,
P7: B2 position,
P8: not inserted
P5: A2 position,
P6: W2 position,
P7: B2 position,
P8: not inserted
P5: A2 position,
P6: W2 position,
P7: B2 position,
P8: not inserted
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R41
1.7kΩ
V
IN
VOUT2
W2 C1
10nF
A2 B2
W
R42
A B
RDAC
, must be negative.
IN
R41
1.7kΩ
VOUT2
R38
2.7kΩ
IN
C1
W2
10nF
B2
W B R42
RDAC
, MUST BE NEGATIVE.
IN
Motherboard
A7: LIN position,
A6: N-INV position,
A8: N-INV position
A7: LOG position,
A6: N-INV position,
A8: N-INV position
A7: LIN position,
A6: INV position,
A8: INV position
UG-624
(5)
V Range
IN
0 V to V
DD
0 V to V
DD
−V to 0 V
DD