AFE5805 Datasheet, PDF (15/53 Pages) Texas Instruments – 8-CHANNEL ANALOG FRONT-END FOR ULTRASOUND

AFE5805
www.ti.com
SBOS421D – MARCH 2008 – REVISED MARCH 2010
TYPICAL CHARACTERISTICS (continued)
AVDD_5V = 5.0V, AVDD1 = AVDD2 = DVDD = 3.3V, LVDD = 1.8V, single-ended input into LNA, ac-coupled with 0.1mF,
V_CNTL = 1.0V, f_IN = 5MHz, clamp disabled, LPF = 15MHz, clock = 40MSPS, 50% duty cycle, internal reference mode,
ISET = 56kΩ, and LVDS buffer setting = 3.5mA, at ambient temperature T_A = +25°C, unless otherwise noted.
GAIN MATCH AT V_CNTL = 1.0V
OUTPUT OFFSET
3500
3000
Channel-to-Channel
4000
3500
2500
2000
1500
1000
3000
2500
2000
1500
1000
500
500
0
0
Gain (dB)
Figure 5.
SNR AND SINAD vs V_CNTL
67
66
PGA = 20dB
65
64
63
Input = -45dBm
Frequency = 5MHz
62
61
60
PGA = 30dB
59
58
57
56
55
0
SNR
SINAD
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2
V_CNTL (V)
Figure 7.
INPUT-REFERRED NOISE vs V_CNTL
130
120
Frequency = 2MHz
110
100
90
80
70
PGA = 20dB
60
50
40
30
20
10 _{PGA = 30dB}
0
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2
V_CNTL (V)
Figure 9.
Code
Figure 6.
INPUT-REFERRED NOISE vs PGA
1.2
R_S = 0W
1.0
V_CNTL = 1.2V
0.8
0.6
0.4
0.2
0
20dB
25dB
27dB
Gain Setting (PGA)
Figure 8.
30dB
INPUT-REFERRED NOISE vs V_CNTL
130
120
Frequency = 5MHz
110
100
90
80
70
60
PGA = 20dB
50
40
30
20
10 _{PGA = 30dB}
0
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2
V_CNTL (V)
Figure 10.
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