MAX4309ESA MAXIM [Maxim Integrated Products], MAX4309ESA Datasheet - Page 10

• Manufacturer Part Number: MAX4309ESA
• Description: 400MHz, Ultra-Low-Distortion Op Amps
• Manufacturer: MAXIM [Maxim Integrated Products]

400MHz, Ultra-Low-Distortion Op Amps
The MAX4108/MAX4109/MAX4308/MAX4309 are opti-
mized for AC performance. They are not designed to
drive highly reactive loads. Reactive loads will
decrease phase margin and may produce excessive
ringing and oscillation. Figure 1a shows a circuit that
Figure 2a. MAX4108 Response vs. Capacitive Load—No
Resistive (R
Figure 2c. MAX4308 Response vs. Capacitive Load—No
Resistive (R
10
______________________________________________________________________________________
S
S
12
10
) Isolation (circuit shown in Figure 1a)
) Isolation (circuit shown in Figure 1a)
-2
-4
-6
-8
-1
-2
-3
-4
-5
-6
8
6
4
2
0
4
3
2
1
0
0.1
0.1
R
A
R
A
S
VCL
S
VCL
= 0
= 0
= +1
= +5
1
1
Driving Capacitive Loads
FREQUENCY (MHz)
FREQUENCY (MHz)
10
10
C
C
L
L
= 15pF
C
= 10pF
C
L
C
L
= 10pF
C
L
= 15pF
L
= 5pF
= 5pF
100
100
1000
1000
eliminates this problem, and Figure 1b is a graph of the
optimal isolation resistor (R
Figures 2a–2d show how a capacitive load causes
excessive peaking of the amplifier’s bandwidth if the
capacitive load is not isolated (R
small isolation resistor (usually 15Ω to 22Ω) placed
Figure 2b. MAX4109 Response vs. Capacitive Load—No
Resistive (R
Figure 2d. MAX4309 Response vs. Capacitive Load—No
Resistive (R
S
S
) Isolation (circuit shown in Figure 1a)
) Isolation (circuit shown in Figure 1a)
20
18
16
14
12
10
-1
-2
-3
-4
-5
-6
8
6
4
2
0
4
3
2
1
0
0.1
0.1
R
A
R
A
S
VCL
S
VCL
= 0
= 0
= +10
= +2
1
1
FREQUENCY (MHz)
FREQUENCY (MHz)
10
10
C
C
S
C
L
L
L
) vs. capacitive load.
= 5pF
= 5pF
C
C
S
= 15pF
C
L
L
L
) from the amplifier. A
= 10pF
= 15pF
= 10pF
100
100
1000
1000