Datasheet

ADA4860-1
Rev. 0 | Page 14 of 20
APPLICATION INFORMATION
POWER SUPPLY BYPASSING
Attention must be paid to bypassing the power supply pins of
the ADA4860-1. High quality capacitors with low equivalent
series resistance (ESR), such as multilayer ceramic capacitors
(MLCCs), should be used to minimize supply voltage ripple
and power dissipation. Generally, a 10 μF tantalum capacitor
located in close proximity to the ADA4860-1 is required to
provide good decoupling for lower frequency signals. In
addition, a 0.1 μF decoupling multilayer ceramic chip capacitor
(MLCC) should be located as close to each of the power supply
pins as is physically possible, no more than ⅛ inch away. The
ground returns should terminate immediately into the ground
plane. Locating the bypass capacitor return close to the load
return minimizes ground loops and improves performance.
FEEDBACK RESISTOR SELECTION
The feedback resistor has a direct impact on the closed-loop
bandwidth and stability of the current feedback op amp circuit.
Reducing the resistance below the recommended value can
make the amplifier response peak and even become unstable.
Increasing the size of the feedback resistor reduces the closed-
loop bandwidth.
Tabl e 5 provides a convenient reference for
quickly determining the feedback and gain set resistor values
and bandwidth for common gain configurations.
Table 5. Recommended Values and Frequency Performance
1
Gain R
F
(Ω) R
G
(Ω)
−3 dB
SS BW
(MHz)
−3 dB
LS BW
(MHz)
Large
Signal
0.1 dB
Flatness
+1 550 N/A 800 165 40
−1 499 499 400 400 80
[phone] 125
+5 348 86.6 335 265 100
+10 348 38.3 165 195 28
1
Conditions: V
S
= ±5 V, T
A
= 25°C, R
L
= 150 Ω.
Figure 51 and Figure 52 show the typical noninverting and
inverting configurations and the recommended bypass
capacitor values.
0
5709-010
0.1µF
10µF
–V
S
V
IN
R
G
V
OUT
10µF
0.1µF
+
V
S
+
ADA4860-1
+
–
R
F
+
Figure 51. Noninverting Gain
0
5709-011
0.1µF
10µF
–V
S
V
IN
V
OUT
10µF
0.1µF
+V
S
ADA4860-1
+
–
R
F
R
G
+
+
Figure 52. Inverting Gain