ADA4937-1 Analog Devices, ADA4937-1 Datasheet - Page 20

• Manufacturer Part Number: ADA4937-1
• Description: Ultra-Low Distortion Differential ADC Driver
• Manufacturer: Analog Devices

ADA4937-1
It is also possible to connect the V
level (CML) output of an ADC. However, care must be taken to
assure that the output has sufficient drive capability. The input
impedance of the V
ADA4937-1 devices share one reference output, it is
recommended that a buffer be used.
Table 9 and Table 10 list several common gain settings,
associated resistor values, input impedance, output noise
density, and approximate large signal bandwidth for both balanced
and unbalanced input configurations. Also shown are the input
common-mode voltage swings under the given conditions for
different V
Table 9. Differential Ground-Referenced Input, DC-Coupled; See Figure 48
Nominal
Gain (dB)
0
3
6
10
12
14
Table 10. Single-Ended Ground-Referenced Input, DC-Coupled, R
Nominal
Gain (dB)
0
3
6
10
12
14
1
R
G2
= R
G1
+ (R
OCM
S
||R
R
(Ω)
200
348
280
348
200
348
316
348
402
348
499
348
R
200
348
280
348
200
348
316
348
402
348
499
348
F
F
T
settings with single 5 V and 3.3 V supplies.
)
(Ω)
R
(Ω)
200
348
200
249
100
174
100
110
100
86.6
100
69.8
OCM
G1
R
200
348
200
249
100
174
100
110
100
86.6
100
69.8
G
pin is approximately 10 kΩ. If multiple
(Ω)
R
(Ω)
61.9
56.2
60.4
59.0
75.0
61.9
73.2
69.8
71.5
71.5
76.8
86.6
T
R
400
696
400
498
200
348
200
220
200
173
200
140
IN, dm
R
(Ω)
267
464
282
351
150
261
161
177
167
144
171
120
OCM
IN,cm
(Ω)
input to a common-mode
R
(Ω)
226
374
226
274
130
200
130
140
130
118
130
100
Differential
Output
Noise Density
(nV/√Hz)
5.8
6.7
7.2
7.6
8.0
9.0
11
12
14
13
17
16
G2
1
Differential
Output
Noise
Density
(nV/√Hz)
5.5
6.5
6.8
7.3
7.0
8.4
9.7
10
12
11
14
12
Approximate
Large-Signal
Bandwidth (MHz)
+V
1500/1100
1500/1100
1400/1100
800/700
500/500
300/300
Rev. 0 | Page 20 of 28
S
= 5 V/3.3 V
Approximate
Large-Signal
Bandwidth
(MHz)
+V
1500/1100
1500/1100
1400/1100
800/700
500/500
300/300
S
= 5 V/3.3 V
S
= 50 Ω; See Figure 49
Note that some gain configurations at 3.3 V cause the input
common-mode voltage to exceed the specified range and should be
avoided. If larger gains are required, other alternatives should be
considered, such as an input common-mode offset, ac coupling,
or a bipolar power supply.
V
0.75 to 1.75
0.69 to 1.40
0.58 to 1.08
0.44 to 0.76
0.37 to 0.62
0.32 to 0.52
V
0.75 to 1.75
0.71 to 1.52
0.66 to 1.31
0.52 to 0.93
0.45 to 0.77
0.39 to 0.65
OCM
OCM
V
= 2.5 V
V
= 2.5 V
OUT, dm
OUT,dm
+V
Common-Mode Swing at +IN, −IN (V)
+V
Common-Mode Swing at +IN, -IN (V)
= 2.0 V p-p
S
= 2.0 V p-p
S
= 5 V
= 5 V
V
1.10 to 2.10
0.98 to 1.69
0.82 to 1.32
0.61 to 0.92
0.51 to 0.76
0.43 to 0.63
V
1.13 to 2.26
1.03 to 1.83
0.94 to 1.59
0.73 to 1.14
0.62 to 0.94
0.53 to 0.79
OCM
OCM
= 3.2 V
= 3.2 V
V
0.40 to 1.20
0.39 to 1.04
0.33 to 0.73
Out of range
Out of range
Out of range
V
0.40 to 1.30
0.39 to 1.04
0.37 to 0.89
0.30 to 0.63
Out of range
Out of range
OCM
OCM
V
= 1.6 V
V
= 1.6 V
OUT, dm
OUT,dm
+V
+V
S
S
= 1.6 V p-p
= 1.6 V p-p
= 3.3 V
= 3.3 V
V
0.50 to 1.30
0.46 to 1.04
0.40 to 0.80
0.31 to 0.56
Out of range
Out of range
V
Out of range
0.48 to 1.13
0.45 to 0.97
0.36 to 0.69
0.31 to 0.57
Out of range
OCM
OCM
= 1.8 V
= 1.8 V