AD844JRZ-16 Analog Devices Inc, AD844JRZ-16 Datasheet - Page 12

• Manufacturer Part Number: AD844JRZ-16
• Description: IC OPAMP CF 60MHZ 80MA 16SOIC
• Manufacturer: Analog Devices Inc

Specifications of AD844JRZ-16

• Slew Rate: 2000 V/µs
• Amplifier Type: Current Feedback
• Number Of Circuits: 1
• -3db Bandwidth: 60MHz
• Current - Input Bias: 200pA
• Voltage - Input Offset: 50µV
• Current - Supply: 6.5mA
• Current - Output / Channel: 80mA
• Voltage - Supply, Single/dual (±): ±4.5 V ~ 18 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 16-SOIC (0.300", 7.5mm Width)
• Op Amp Type: High Speed
• No. Of Amplifiers: 1
• Bandwidth: 60MHz
• Supply Voltage Range: ± 4.5V To ± 18V
• Amplifier Case Style: SOIC
• No. Of Pins: 16
• Operating Temperature Range: 0°C To
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Output Type: -
• Gain Bandwidth Product: -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

AD844
Noise
Noise sources can be modeled in a manner similar to the dc bias
currents, but the noise sources are I
induced noise at the output, V
Overall noise can be reduced by keeping all resistor values to a
minimum. With typical numbers, R1 = R2 = 1 kΩ, R
V
V
this case, since it will be in most low gain applications.
Video Cable Driver Using
The AD844 can be used to drive low impedance cables. Using
± 5 V supplies, a 100 Ω load can be driven to ± 2.5 V with low
distortion. Figure 11a shows an illustrative application that
provides a noninverting gain of +2, allowing the cable to be
reverse-terminated while delivering an overall gain of +1 to the
load. The –3 dB bandwidth of this circuit is typically 30 MHz.
Figure 11b shows a differential gain and phase test setup. In
video applications, differential-phase and differential-gain
characteristics are often important. Figure 11c shows the varia-
tion in phase as the load voltage varies. Figure 11d shows the
gain variation.
N
ON
Figure 11b. Differential Gain/Phase Test Setup Figure
= 2 nV/√Hz, I
GENERATOR
STAIRCASE
calculates to 12 nV/√Hz. The current noise is dominant in
ANALYZER
NETWORK
HP3314A
HP8753A
V
ON
V
EXT
TRIG
SYNC OUT
Figure 11a. The AD844 as a Cable Driver
IN
=
50
((
RF OUT
RF IN
OUT
I
NP
NP
3
2
R
= 10 pA/√Hz, I
(TERMINATOR)
P
–5V
+5V
)
2
7
4
OUT
+
IN
6
V
2.2 F
5 V Supplies
2.2 F
N
ON
50
HP11850C
SPLITTER
2
, is:
)



NN
1
300
300
OUT
50
+
, I
NN
R
R
NP
Z
1
2
OUT
O
= 12 pA/√Hz, and
, V

 +

= 50
2
N
V
V
, and the amplifier
IN
470
IN
(
I
NN
R
50
CIRCUIT
UNDER
L
TEST
V
R
OUT
1
)
2
P
V
= 0,
OUT
–12–
High Speed DAC Buffer
The AD844 performs very well in applications requiring
current-to-voltage conversion. Figure 12 shows connections for
use with the AD568 current output DAC. In this application,
the bipolar offset is used so that the full-scale current is ± 5.12 mA,
which generates an output of ± 5.12 V using the 1 kΩ applica-
tion resistor on the AD568. Figure 13 shows the full-scale
transient response. Care is needed in power supply decoupling
and grounding techniques to achieve the full 12-bit accuracy
and realize the fast settling capabilities of the system. The
unmarked capacitors in this figure are 0.1 µF ceramic (for
example, AVX Type SR305C104KAA), and the ferrite induc-
tors should be about 2.5 µH (for example, Fair-Rite Type
2743002122). The AD568 data sheet should be consulted for
more complete details about its use.
Figure 11c. Differential Phase for the Circuit of Figure 11a
Figure 11d. Differential Gain for the Circuit of Figure 11a
–0.06
–0.02
–0.04
0.06
0.04
0.02
–0.1
–0.2
–0.3
0.3
0.2
0.1
0
0
0
0
IRE = 7.14mV
IRE = 7.14mV
18
18
36
36
V
V
OUT
OUT
– IRE
– IRE
54
54
72
72
90
REV. E
90