MAX2038
Ultrasound VGA Integrated
with CW Octal Mixer
_______________________________________________________________________________________ 9
0
-5
-10
-15
-20
-25
-30
-35
-40
0.1 10 1001 1000
LARGE-SIGNAL BANDWIDTH
vs. FREQUENCY
MAX2038 toc17
FREQUENCY (MHz)
GAIN (dB)
V
OUT
= 0.5V
P-P
DIFFERENTIAL
VG_CTL = +2V
P-P
DIFFERENTIAL
-100
-80
-90
-60
-70
-40
-50
-30
-10
-20
0
01.50.5 1.0 2.0 2.5 3.0
HARMONIC DISTORTION
vs. DIFFERENTIAL OUTPUT VOLTAGE
MAX2038 toc18
DIFFERENTIAL OUTPUT VOLTAGE (V
P-P
)
HARMONIC DISTORTION (dBc)
THIRD HARMONIC
SECOND HARMONIC
V
OUT
= 1V
P-P
DIFFERENTIAL
f = 5MHz, GAIN = 10dB
-100
-90
-95
-80
-85
-70
-75
-65
-50
-60
-45
-55
-40
200 1100500 800 1400 1700 2000
HARMONIC DISTORTION
vs. DIFFERENTIAL OUTPUT LOAD RESISTANCE
MAX2038 toc19
DIFFERENTIAL OUTPUT LOAD (
Ω
)
HARMONIC DISTORTION (dBc)
THIRD HARMONIC
SECOND HARMONIC
V
OUT
= 1V
P-P
DIFFERENTIAL
f = 5MHz, GAIN = 10dB
Typical Operating Characteristics (continued)
(Figure 7, V
CC
= V
REF
= 4.75V to 5.25V, V
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
values are at V
CC
= V
REF
= 5V, T
A
= +25°C, unless otherwise noted.)
-100
-90
-95
-80
-85
-70
-75
-65
-45
-50
-55
-60
-40
56525 45 85 105
HARMONIC DISTORTION
vs. DIFFERENTIAL OUTPUT LOAD CAPACITANCE
MAX2038 toc20
DIFFERENTIAL OUTPUT LOAD (pF)
HARMONIC DISTORTION (dBc)
THIRD HARMONIC
SECOND HARMONIC
V
OUT
= 1V
P-P
DIFFERENTIAL
f = 5MHz, GAIN = 10dB
-100
-80
-90
-60
-70
-40
-50
-30
-10
-20
0
02010 30 40 50
HARMONIC DISTORTION
vs. FREQUENCY
MAX2038 toc21
FREQUENCY (MHz)
HARMONIC DISTORTION (dBc)
V
OUT
= 1V
P-P
DIFFERENTIAL
GAIN = 10dB
THIRD HARMONIC
SECOND HARMONIC
-70
-60
-50
-40
-10
-20
-30
0
015510 2025
TWO-TONE ULTRASOUND-SPECIFIC IMD3
vs. FREQUENCY
MAX2038 toc22
FREQUENCY (MHz)
IMD3 (dBc)
V
OUT
= 1V
P-P
DIFFERENTIAL
GAIN = 10dB
0
20
15
50
10
5
25
30
35
40
45
0.40
-0.40
-0.35
-0.30
-0.25
-0.20
-0.15
-0.10
-0.05
0.05
0.10
0.15
0.20
0.25
0.30
0.35
GAIN ERROR HISTOGRAM
MAX2038 toc23
GAIN ERROR (dB)
% OF UNITS
SAMPLE SIZE = 202 UNITS,
f
IN_
= 5MHz, GAIN = 10dB
-20
-10
-15
0
-5
10
5
15
20
-15 5-5 15 25 35
OUTPUT COMMON-MODE OFFSET VOLTAGE
vs. GAIN
MAX2038 toc24
GAIN (dB)
OFFSET VOLTAGE (mV)
0.1 10 100
DIFFERENTIAL OUTPUT IMPEDANCE
MAGNITUDE vs. FREQUENCY
MAX2038 toc25
FREQUENCY (MHz)
|
Z
OUT|
1
200
60
80
100
120
140
180
160
