
Complete 450MHz Quadrature Transmitter
Typical Operating Characteristics
(MAX2370 EV kit, V CC_ = SHDN = IDLE = TXGATE = CS = 3.0V, f REF = 19.2MHz, LO input power = -15dBm, f LO = 575MHz, f RFOUT =
455MHz, f IF = 120MHz, R BIAS = 10k ? , V GC = 2.5V, registers set according to Table 1, input voltage at I and Q = 130mV RMS differential,
T A = +25 ° C, unless otherwise noted.)
RF OUTPUT POWER AND SUPPLY CURRENT
vs. GAIN-CONTROL VOLTAGE
IF OUTPUT POWER AND IF ACPR
vs. GAIN-CONTROL VOLTAGE
RF OUTPUT POWER AND RF ACPR
vs. GAIN-CONTROL VOLTAGE
20
MAX2370 toc01
170
0
20
-10
10
0
POWER
150
-20
POWER
0
-10
POWER
-20
130
-30
-20
ACPR ± 885kHz
ACPR ± 885kHz
-40
-60
-80
CURRENT
110
90
70
-40
-50
-60
-70
ACPR ± 1.125MHz
ACPR ± 1.98MHz
-30
-40
-50
-60
-70
ACPR ± 1.125MHz
ACPR ± 1.98MHz
-80
-80
-100
50
-90
-90
1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 3.0
2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.1
2.2
2.3
2.4
2.5
2.6
2.7
V GC (V)
RF GAIN, IMAGE SUPPRESSION, AND LO
SUPPRESSION vs. FREQUENCY
V GC (V)
NORMALIZED IF OUTPUT POWER vs. IFG[2:0]
V GC (V)
RFOUT PORT S22
30
25
20
15
10
5
0
GAIN
IMAGE SUPPRESSION
LO SUPPRESSION
MAX2370 toc04
0
-10
-20
-30
-40
-50
-60
0
-2
-4
-6
-8
-10
-12
-14
-16
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
MAGNITUDE
PHASE
MAX2370 toc06
0
-10
-20
-30
-40
-50
-60
-70
-80
-90
-100
400 410 420 430 440 450 460 470 480 490 500
0
1
2
3
4
5
6
7
400 410 420 430 440 450 460 470 480 490 500
RF FREQUENCY (MHz)
IFG[2:0] (DECIMAL)
FREQUENCY (MHz)
1.0
0.9
RFPLL PORT S11
MAX2370 toc07
0
-10
1.0
0.9
LO PORT S11
MAX2370 toc08
0
-10
-10
-20
IF OUTPUT SPECTRUM
P OUT = -12dBm
0.8
-20
0.8
-20
-30
0.7
0.6
0.5
0.4
0.3
0.2
0.1
MAGNITUDE
PHASE
-30
-40
-50
-60
-70
-80
-90
0.7
0.6
0.5
0.4
0.3
0.2
0.1
PHASE
MAGNITUDE
-30
-40
-50
-60
-70
-80
-90
-40
-50
-60
-70
-80
-90
-100
0
1050
1100
1150
1200
1250
1300
-100
0
500 520 540 560 580 600 620 640 660 680 700
-100
-110
FREQUENCY
FREQUENCY (MHz)
FREQUENCY (MHz)
CENTER: 120MHz, SPAN: 5MHz, RBW: 30kHz
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