ADA4941-1YRZ-R7 Analog Devices Inc, ADA4941-1YRZ-R7 Datasheet - Page 17

• Manufacturer Part Number: ADA4941-1YRZ-R7
• Description: Amplifier, Other
• Manufacturer: Analog Devices Inc
• Type: ADC Driverr

Specifications of ADA4941-1YRZ-R7

• Design Resources: Converting a Single-Ended Signal with AD7982 Differential PulSAR ADC (CN0032) Converting a Single-Ended Signal with AD7984 Differential PulSAR ADC (CN0033)
• Applications: Data Acquisition
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Table 7, Table 8, and Table 9 show typical error budgets for the
circuits shown in Figure 48, Figure 49, and Figure 50.
R
Table 7. Output Voltage Error Budget for G = 2.4 Amplifier
Shown in Figure 48
Error
Source
V
I
I
V
Total V
R
Table 8. Output Voltage Error Budget for Amplifier Shown
in Figure 49
Error
Source
V
I
I
V
Total V
R
Table 9. Output Voltage Error Budget for G = 5 Amplifier
Shown in Figure 50
Error
Source
V
I
I
V
Total V
OUTPUT VOLTAGE NOISE
√4kTR
BP
BN
BP
BN
BP
BN
OS
OS
OS
OS
OS
OS
F
F
F
_A1
_A1
_A1
_A1
_A1
_A1
= 1.0 kΩ, R
= 0 Ω, R
= 1.02 kΩ, R
_A1
_A2
_A1
_A2
_A1
_A2
G
R
O
O
O
G
_error, dm = 0.44 mV
_error, dm = 0.4 mV
_error, dm = 0.7 mV
Typical
Value
0.1 mV
3 μA
3 μA
0.1 mV
Typical
Value
0.1 mV
3 μA
3 μA
0.1 mV
Typical
Value
0.1 mV
3 μA
3 μA
0.1 mV
R
1
8
√4kTR
S
G
= ∞, R
FB
IN
G
S
√4kTR
G
= 4.99 kΩ, R
= 665 Ω, R
vn
in
ip
F
–
–
–
S
A1
A1
A1
_IN = 0 Ω, R
VOP_error
+0.12 mV
+2.48 mV
−2.48 mV
0 mV
VOP_error
+0.1 mV
+2.48 mV
−2.48 mV
0 mV
VOP_error
+0.25 mV
+1.21 mV
−1.21 mV
0 mV
Figure 52. Noise Sources
R
R
F
A1
S–
REF
2
S
S
_IN = 402 Ω, R
_IN = 825 Ω, R
REF
√4kT (500Ω)
√4kT (R
√4kT (1kΩ)
S
_REF = 0 Ω
VON_error
−0.12 mV
−2.48 mV
+2.48 mV
+0.2 mV
VON_error
−0.1 mV
−2.48 mV
+2.48 mV
+0.2 mV
VON_error
−0.25 mV
−1.21 mV
+1.21 mV
+0.2 mV
S–
REF)
in
ip
500Ω
1kΩ
–
–
A2
A2
S
vn
S
_REF = 0 Ω
_REF = 0 Ω
–
√4kT (1kΩ)
A2
V
+0.24 mV
−4.96 mV
+4.96 mV
+0.2 mV
V
+0.2 mV
−4.96 mV
+4.96 mV
+0.2 mV
V
+0.5 mV
−2.4 mV
+2.4 mV
+0.2 mV
O
O
O
A2
_dm_error
_dm_error
_dm_error
1kΩ
OUT+
OUT–
VOP
VON
+
–
+
–
Rev. B | Page 17 of 24
4
5
Figure 52 shows the major contributors to the ADA4941-1
differential output voltage noise. The differential output noise
mean-square voltage equals the sum of twice the noise mean-
square voltage contributions from the noninverting channel
(A1), plus the noise mean-square voltage terms associated with
the inverting channel (A2).
where VON_n
where:
vn_A1 and vn_A2 are the input voltage noises of A1 and A2,
each equal to 2.1 nV/√Hz.
in_A1 , in_A2 , ip_A1 , and ip_A2 are amplifier input current
noise terms, each equal to 1 pA/√Hz.
R
resistors, respectively.
kT is Boltzmann’s constant times absolute temperature, equal to
4.2 x 10
R
When A1 is used as a unity gain follower, the output voltage
noise spectral density is at its minimum, 10 nV/√Hz. Higher
voltage gains have higher output voltage noise.
Table 10, Table 11, and Table 12 show the noise contributions
and output voltage noise for the circuits in Figure 48, Figure 49,
and Figure 50.
S
S
, R
_REF is any source resistance at the REF pin.
F
V
2
2
VON_n
⎡
⎢
⎢
⎣
⎡
⎢
⎢
⎢
, and R
4
8
⎛
⎜
⎜
⎝
⎛
⎜
⎜
⎝
O
⎡
⎢
⎢
⎣
[
1
1
[
⎛
⎜
⎜
⎝
(
-21
,
kT
1
ip
dm
+
+
4
+
W-s at room temperature.
_
(1000)
kTR
R
R
R
R
_
R
R
G
G
A2
F
F
G
2
n
G
F
are the external source, feedback, and gain
⎞
× ⎟ ⎟
⎠
⎞
⎟
⎟
⎠
=
2
2
F
)(
⎞
× ⎟ ⎟
⎠
×
is calculated as
4
]
=
2
500
(
+
ip
(
+
(
vn_A2
4
vn
16
_
2
kTR
+
A1
_
⎡
⎢
⎣
kT
R
A1
S
4
×
S
2
(500)
_
)
)
⎤
⎥
⎥
⎥
R
kTR
⎤
⎥
⎥
⎦
2
REF
+
S
2
+
)
+
⎤
⎥
⎥
⎦
G
VON
2
+
2
)
+
×
] [
16
2
×
2
R
+
R
kT
[
G
F
in
_
1000
⎤
⎥
⎦
n
(
_
2
2
R
A1
+
S
_REF
2
(
×
in
×
R
_
ADA4941-1
F
A2
)
]
2
+
)
]
2
+
(13)
(14)