ADA4862-3 Analog Devices, ADA4862-3 Datasheet - Page 11

• Manufacturer Part Number: ADA4862-3
• Description: High Speed, G = +2, Low Cost, Triple Op Amp
• Manufacturer: Analog Devices

Specifications of ADA4862-3

• -3db Bandwidth: 310MHz
• Slew Rate: 830V/µs
• Vos: 2mV
• Ib: 600nA
• # Opamps Per Pkg: 3
• Input Noise (nv/rthz): 10.6nV/rtHz
• Vcc-vee: 5V to 12V
• Isy Per Amplifier: 6.83mA
• Packages: SOIC

APPLICATIONS
USING THE ADA4862-3 IN GAINS = +1, −1
The ADA4862-3 was designed to offer outstanding video
performance, simplify applications, and minimize board area.
The ADA4862-3 is a triple amplifier with on-chip feedback and
gain set resistors. The gain is fixed internally at G = +2. The
inclusion of the on-chip resistors not only simplifies the design
of the application but also eliminates six surface-mount
resistors, saving valuable board space and lowers assembly
costs. A typical schematic is shown in Figure 29.
While the ADA4862-3 has a fixed gain of G = +2, it can be used
in other gain configurations, such as G = −1 and G = +1, which
are discussed next.
Unity-Gain Operation (Option 1)
There are two options for obtaining unity gain (G = +1). The
first is shown in Figure 30. In this configuration, the –IN input
pin is left floating (feedback is provided via the internal 550 Ω),
and the input is applied to the noninverting input. The noise
gain for this configuration is 1. Frequency performance and
transient response are shown in Figure 31 through Figure 33.
V
IN
Figure 29. Noninverting Configuration (G = +2)
V
IN
Figure 30. Unity Gain of Option 1
R
T
R
T
GAIN OF +1
GAIN OF +2
+V
–V
+V
–V
S
S
0.01μF
0.01μF
S
S
10μF
10μF
0.01μF
0.01μF
10μF
10μF
V
OUT
V
OUT
Rev. A | Page 11 of 16
Figure 33. Large Signal Transient Response for Various Capacitor Loads
–0.5
–1.0
–1.5
–2.0
2.0
1.5
1.0
0.5
–1
–2
–3
–4
–1
–2
–3
–4
–5
–6
0
4
3
2
1
0
3
2
1
0
0.1
0.1
G = +1
R
C
V
G = +1
R
C
V
OUT
L
L
L
L
OUT
= 150Ω
= 4pF
= 150Ω
= 4pF
G = +1
R
V
V
TIME = 5ns/DIV
= 2V p-p
= 200mV p-p
Figure 31. Small Signal Unity Gain
OUT
S
L
Figure 32. Large Signal Gain +1
= ±5V
= 150Ω
= 2V p-p
C
1
1
L
C
= 9pF
L
C
= 6pF
L
= 4pF
FREQUENCY (MHz)
FREQUENCY (MHz)
10
10
V
S
V
= +5V
S
= +5V
100
100
V
ADA4862-3
S
= ±5V
V
S
= ±5V
1000
1000