AD8331_10 Datasheet, PDF (15/56 Pages) Analog Devices – Ultralow Noise VGAs with Preamplifier and Programmable RIN

500
f = 10MHz
400
300
HI GAIN
AD8332
AD8334
LO GAIN
AD8331
200
100
0
0
0.2
0.4
0.6
0.8
1.0
V_GAIN (V)
Figure 25. Output-Referred Noise vs. VGAIN
2.5
R_S = 0, R_IZ = ∞, V_GAIN = 1V,
HILO = LO OR HI
2.0
1.5
1.0
0.5
100k
1M
10M
FREQUENCY (Hz)
100M
Figure 26. Short-Circuit, Input-Referred Noise vs. Frequency
100
R_S = 0, R_IZ = ∞,
HILO = LO OR HI, f = 10MHz
10
1
0.1
0
0.2
0.4
0.6
0.8
1.0
V_GAIN (V)
Figure 27. Short-Circuit, Input-Referred Noise vs. VGAIN
AD8331/AD8332/AD8334
1.00 _{RS = 0, RIZ = ∞,}
0.95 ^VGAIN ^{= 1V, f = 10MHz}
0.90
0.85
0.80
0.75
0.70
0.65
0.60
0.55
0.50
–50
–30
–10
10
30
50
70
90
TEMPERATURE (°C)
Figure 28. Short-Circuit, Input-Referred Noise vs. Temperature
10
f = 5MHz, R_IZ = ∞,
V_GAIN = 1V
1
R_S THERMAL NOISE
ALONE
0.1
1
10
100
1k
SOURCE RESISTANCE (Ω)
Figure 29. Input-Referred Noise vs. RS
7
INCLUDES NOISE OF VGA
6
5
R_IN = 50Ω
4
R_IN = 75Ω
3
R_IN = 100Ω
R_IN = 200Ω
2
R_IZ = ∞
1
SIMULATED RESULTS
0
50
100
1k
SOURCE RESISTANCE (Ω)
Figure 30. Noise Figure vs. RS for Various Values of RIN
Rev. G | Page 15 of 56