AD830JRZ-R7 Analog Devices Inc, AD830JRZ-R7 Datasheet - Page 16

• Manufacturer Part Number: AD830JRZ-R7
• Description: IC,Video Amplifier,HYBRID,SOP,8PIN,PLASTIC
• Manufacturer: Analog Devices Inc

Specifications of AD830JRZ-R7

• Applications: Differential
• Number Of Circuits: 1
• -3db Bandwidth: 85MHz
• Slew Rate: 360 V/µs
• Current - Supply: 14.5mA
• Current - Output / Channel: 50mA
• Voltage - Supply, Single/dual (±): 8 V ~ 33 V, ±4 V ~ 16.5 V
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (0.154", 3.90mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: AD830JRZ-R7; AD830JRZ-R7TR

AD830
stability and also keep bias current induced offsets low. Highest
CMRR and lowest dc offsets are preserved by including a
compensating resistor in series with Pin 3. The gain may be as
high as 100.
Offsetting the Output With Gain
Some applications, such as ADCs, require that the signal be
amplified and also offset, typically to accommodate the input
range of the device. The AD830 can offset the output signal
very simply through Pin 3 even with gain > 1. The voltage
applied to Pin 3 must be attenuated by an appropriate factor so
that V
from a voltage reference is used to produce the attenuated offset
voltage.
Loop Through or Line Bridging Amplifier (Figure 42)
The AD830 is ideally suited for use as a video line bridging
amplifier. The video signal is tapped from the conductor of the
cable relative to its shield. The high input impedance of the
AD830 provides negligible loading on the cable. More significantly,
the benign loading is maintained while the AD830 is powered
down. Coupled with its good video load driving performance,
the AD830 is well suited for video cable monitoring applications.
V
CM
V
CM
Z
CM
3
Z
CM
× G = desired offset. In Figure 41, a resistive divider
Figure 41. Offsetting the Output with Differential Gain >1
SIGNAL
INPUT
V
V
SIGNAL
1
2
V
R
V
INPUT
V
Figure 40. Gain of G Differential Amplifier, G>1
OUT
1
1
2
V
R
R
OUT
1
2
= (V
R
1
2
3
4
2
= (V
1
– V
1
2
3
4
1
– V
2
)(1 + R
G
G
2
M
M
)(1 + R
G
G
M
M
1
/R
1
2
/R
)
2
)
C
AD830
A = 1
C
AD830
A = 1
8
7
6
5
8
7
6
5
V
V
P
0.1µF
N
0.1µF
V
V
P
N
0.1µF
0.1µF
R
2
V
OUT
R
V
1
OUT
R
R
1
V
2
R
R
V
REF
3
3
4
Rev. C | Page 16 of 20
Resistorless Summing
Direct, two input, resistorless summing is easily realized from
the general unity gain mode. By grounding V
two inputs to V
applied voltages, V
A diagram of this simple but potent application is shown below
in Figure 43. The AD830 summing circuit possesses several
virtues not present in the classic op amp based summing circuits.
It has high impedance inputs, no resistors, very precise summing,
high reverse isolation, and noninverting gain. Achieving this
function and performance with op amps requires significantly
more components.
2× Gain Bandwidth Line Driver
A gain of two, without the use of resistors, is possible with the
AD830. This is accomplished by grounding V
and V
wired connection. The output is exactly twice the applied
voltage, V
for this highly useful application. The most notable characteristic of
this alternative gain of +2 is that there is no loss of bandwidth as
in a voltage feedback op amp based gain of +2 where the
bandwidth is halved; therefore, the gain bandwidth is doubled.
In addition, this circuit is accurate without the need for any
precise valued resistors, as in the op amp equivalents, and it
possesses excellent differential gain and phase performance, as
shown in Figure 45 and Figure 46.
R
G
249Ω
Y1
V
inputs together, and applying the input, V
V
3
1
IN
1
2
3
4
; V
OUT
Figure 43. Resistorless Summing Amplifier
X1
G
G
and V
= 2 × V
M
M
1
2
3
4
1
Figure 42. Cable Tap Amplifier
and V
OPTIONAL C
Y1
G
G
, the output is the exact sum of the
M
M
IN
3
, relative to common; V
. Figure 44 shows the connections
C
V
AD830
A = 1
OUT
= V
C
1
C
AD830
+V
A = 1
8
7
6
5
3
V
V
P
0.1µF
N
0.1µF
V
OUT
8
7
6
5
X2
X2
V
V
, tying the V
75Ω
499Ω
499Ω
and applying the
P
N
OUT
IN
OUT
, to this
= V
75Ω
1
+ V
X1
3
.