AD8672 Analog Devices, AD8672 Datasheet - Page 12

• Manufacturer Part Number: AD8672
• Description: Dual Precision Very Low Noise, Low Input Bias Current Operational Amplifier
• Manufacturer: Analog Devices

Specifications of AD8672

• -3db Bandwidth: 10MHz
• Slew Rate: 4V/µs
• Vos: 20µV
• Ib: 3nA
• # Opamps Per Pkg: 2
• Input Noise (nv/rthz): 2.8nV/rtHz
• Vcc-vee: 10V to 36V
• Isy Per Amplifier: 3.5mA
• Packages: SOIC,SOP

AD8671/AD8672/AD8674
OUTPUT PHASE REVERSAL
Phase reversal is a change of polarity in the amplifier transfer
function that occurs when the input voltage exceeds the supply
voltage. The AD8671/AD8672/AD8674 do not exhibit phase
reversal even when the input voltage is 1 V beyond the supplies.
Figure 33. Output Phase Reversal
TIME (10μs/DIV)
V
IN
V
OUT
V
SY
= ±15V
Rev. E | Page 12 of 20
TOTAL NOISE VS. SOURCE RESISTANCE
The low input voltage noise of the AD8671/AD8672/AD8674
makes them a great choice for applications with low source
resistance. However, because they have low input current noise,
they can also be used in circuits with substantial source
resistance.
Figure 34 shows the voltage noise, current noise, thermal noise,
and total rms noise of the AD8671 as a function of the source
resistance.
For R
For 475 Ω < R
For R
1000
S
S
100
10
< 475 Ω, the input voltage noise, e
> 412 kΩ, the input current noise dominates.
1
10
S
< 412 kΩ, thermal noise dominates.
Figure 34. Noise vs. Source Resistance
100
e
n_t
SOURCE RESISTANCE (Ω)
A
1k
(4kR
S
T)
10k
1/2
B
n
, dominates.
100k
e
n
C
i
n
1M