MAX2035 Datasheet, PDF (7/12 Pages) Maxim Integrated Products – Ultrasound Variable-Gain Amplifier

Ultrasound Variable-Gain Amplifier
Typical Operating Characteristics (continued)
(Figure 2, V_CC = V_REF = 4.75V to 5.25V, GND = 0V, PD = 0, VG_CLAMP_MODE = 1, f_RF = 5MHz, capacitance to GND at each of the
VGA differential outputs is 60pF, differential capacitance across the VGA outputs is 10pF, R_L = 1kΩ, T_A = 0°C to +70°C. Typical val-
ues are at V_CC = V_REF = 5V, V_CM = 3.0V, T_A = +25°C, unless otherwise noted.)
HARMONIC DISTORTION
vs. DIFFERENTIAL OUTPUT LOAD RESISTANCE
-40
-45 ^VOUT ^{= 1V}P-P ^DIFFERENTIAL
-50 ^{f = 5MHz, GAIN = 20dB}
-55
-60
THIRD HARMONIC
-65
-70
-75
SECOND HARMONIC
-80
-85
-90
-95
-100
200 500 800 1100 1400 1700 2000
DIFFERENTIAL OUTPUT LOAD (Ω)
HARMONIC DISTORTION
vs. DIFFERENTIAL OUTPUT LOAD CAPACITANCE
-40
-45 ^VOUT ^{= 1V}P-P ^DIFFERENTIAL
-50 ^{f = 5MHz, GAIN = 20dB}
-55
-60
THIRD HARMONIC
-65
-70
-75
SECOND HARMONIC
-80
-85
-90
-95
-100
5
25
45
65
85
105
DIFFERENTIAL OUTPUT LOAD (pF)
HARMONIC DISTORTION
vs. FREQUENCY
0
-10
V_OUT = 1V_P-P DIFFERENTIAL
GAIN = 20dB
-20
THIRD HARMONIC
-30
-40
-50
-60
SECOND HARMONIC
-70
-80
-90
-100
0
10
20
30
40
50
FREQUENCY (MHz)
TWO-TONE ULTRASOUND-SPECIFIC IMD3
vs. FREQUENCY
0
V_OUT = 1V_P-P DIFFERENTIAL
-10 ^{GAIN = 20dB}
-20
-30
-40
-50
-60
-70
0
5
10
15
20
25
FREQUENCY (MHz)
GAIN ERROR HISTOGRAM
50
45
SAMPLE SIZE = 188 UNITS
f_{IN_} = 5MHz, GAIN = 20dB
40
35
30
25
20
15
10
5
0
-4.50 -3.00 -1.50 0.75 2.25 3.75
-3.75 -2.25 -0.75 1.50 3.00 4.50
GAIN ERROR (dB)
OUTPUT COMMON-MODE OFFSET VOLTAGE
vs. GAIN
100
DIFFERENTIAL OUTPUT IMPEDANCE
MAGNITUDE vs. FREQUENCY
200
75
180
50
25
0
-25
-50
-75
-100
-15 -5
5 15 25 35 45
GAIN (dB)
160
140
120
100
80
60
0.1
1
10
100
FREQUENCY (MHz)
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