AD8045 Analog Devices, AD8045 Datasheet - Page 18

• Manufacturer Part Number: AD8045
• Description: 3 nV/?Hz Ultralow Distortion Voltage Feedback High Speed Amplifier
• Manufacturer: Analog Devices

Specifications of AD8045

• -3db Bandwidth: 1GHz
• Slew Rate: 1350V/µs
• Vos: 200µV
• Ib: 2µA
• # Opamps Per Pkg: 1
• Input Noise (nv/rthz): 3nV/rtHz
• Vcc-vee: 3.3V to 12V
• Isy Per Amplifier: 19mA
• Packages: CSP,SOIC

AD8045
OUTPUT NOISE
Figure 66 shows the contributors to the noise at the output of a
noninverting configuration.
V
RS
R
S
I
I
EN
EN
+
–
Figure 66. Amplifier DC Errors
R
V
V
V
G
EN
RF
RG
R
F
+
V
OUT
–
Rev. A | Page 18 of 24
source resistor, R
rms sum of all the contributions.
where:
G
Table 7 lists the expected output voltage noise spectral density
for several gain configurations.
Table 7. Noise and Bandwidth for Various Gains
Gain
+1
+2
+5
+10
−1
1
Ven , IN+ , and IN− are due to the amplifier.
V
V
Ven is the op amp input voltage noise.
IN is the op amp input current noise.
R
(
OUT
G
n
R
L
n
S
is the noise gain
= 1 kΩ.
×
Ven
are due to the feedback network resistors. R
_
EN
) (
2
+
R
0
499
499
499
499
=
IN
F
+
×
R
S
×
S
. Total output voltage noise,
R
−
499
124
56
499
G
n
G
) (
2
⎛
⎜
⎝
+
R
IN
F
R
+
−
G
R
100
0
0
0
N/A
×
R
R
S
G
F
||R
⎞
⎟
⎠
G
.
×
G
n
−3 dB
Bandwidth
1 GHz
400 MHz
90 MHz
40 MHz
300 MHz
)
2
+
4
kTR
f
+
4
kTR
V
1
V
R
G
OUT
F
( )
G
G
,
n
V
and R
2
Output
Noise
(nV/√Hz)
3.3
7.4
16.4
31
7.4
_
+
R
EN
4
G
kTR
, and
F
, is the
S
, and
( )
G
n
2