Datasheet

Data Sheet ADA4891-1/ADA4891-2/ADA4891-3/ADA4891-4
Rev. E | Page 11 of 24
0.01
0.1
1
10
100
0.01 0.1 1 10 100
FREQUENCY (MHz)
V
S
= 5V
G = +1
OUTPUT IMPEDANCE (Ω)
08054-046
Figure 31. Closed-Loop Output Impedance vs. Frequency, Part Enabled
OUTPUT VOLTAGE (mV)
100
0
–100
G = +1
V
OUT
= 200mV p-p
R
L
= 1kΩ
V
S
= 3V
08054-048
V
S
= 5V
50mV/DIV 5ns/DIV
Figure 32. Small-Signal Step Response, G = +1
OUTPUT VOLTAGE (V)
1
0
–1
V
S
= 5V
G = +1
V
OUT
= 2V p-p
R
L
= 150Ω
R
L
= 1kΩ
08054-049
0.5V/DIV
5ns/DIV
Figure 33. Large-Signal Step Response, V
S
= 5 V, G = +1
100k
10k
1k
100
10
1
0.01 0.1 1 10 100
OUTPUT IMPEDANCE (Ω)
FREQUENCY (MHz)
08054-089
V
S
= 5V
G = +1
Figure 34. Closed-Loop Output Impedance vs. Frequency, Part Disabled
(ADA4891-3 Only)
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
10 20
30 40 50
60 70 80 90
TIME (ns)
OUTPUT VOLTAGE (V)
08054-047
V
S
= 5V
R
L
= 1kΩ
V
S
= 5V
R
L
= 150Ω
V
S
= 3V
R
L
= 150Ω
V
S
= 3V
R
L
= 1kΩ
G = +2
V
OUT
= 2V p-p
Figure 35. Large-Signal Step Response, G = +2
0.5
0
–0.5
OUTPUT VOLTAGE (V)
R
L
= 150Ω
R
L
= 1kΩ
V
S
= 3V
G = +1
V
OUT
= 1V p-p
08054-050
0.5V/DIV
5ns/DIV
Figure 36. Large-Signal Step Response, V
S
= 3 V, G = +1