
Low-Voltage IF Transceiver
with Limiter and RSSI
____________________________Typical Operating Characteristics (continued)
(MAX2511 test fixture, V CC = +3.0V, 0.01μF across CZ and CZ , MIXOUT tied to VREF through 165 ? resistor, TXIN, TXIN tied to
VREF through 50 ? resistor, TXOUT and TXOUT loaded with 100 ? differential, GC open, LIMOUT, LIMOUT loaded with 2k ? differ-
ential, TANK and TANK driven with -2.5dBm from a 100 ? source; OSCOUT AC-terminated with 50 ? , 100pF at RSSI pin, 0.1μF at
VREF pin, Rx inputs and Tx outputs differentially coupled, P RXIN, RXIN = -28dBm (200 ? system), f RXIN, RXIN = 425MHz, f LO = 435.7MHz,
f TXIN, TXIN = 10.7MHz, T A = +25°C, unless otherwise noted.)
DOWNCONVERTER-MIXER IMAGE
45
DOWNCONVERTER IMAGE REJECTION
vs. RXIN FREQUENCY
40
REJECTION vs. TEMPERATURE
AND SUPPLY VOLTAGE
40
DOWNCONVERTER IMAGE REJECTION
vs. IF FREQUENCY
38
35
TXEN = LOW
RXEN = HIGH
40
35
36
34
V CC = 5.5V
V CC = 2.7V
30
25
20
32
15
30
25
30
28
26
V CC = 3.0V
10
5
0
200
250
300
350
400 425
-40
-20
0
20
40
60
85
0
10
20
30
40
50
FREQUENCY (MHz)
DOWNCONVERTER INPUT 1dB
COMPRESSION LEVEL
TEMPERATURE (°C)
RXIN DIFFERENTIAL INPUT IMPEDANCE
vs. FREQUENCY
IF FREQUENCY (MHz)
LIMITER OUTPUT LEVEL
vs. GC VOLTAGE
70
60
50
40
T A = -40°C
T A = +25°C
T A = +85°C
250
200
150
100
50
0
RX MODE REAL
RX OFF REAL
1.2
1.0
.8
.6
T A = -40°C
T A = +25°C
T A = +85°C
30
-50
20
TXEN = LOW
-100
RX MODE IMAGINARY
.4
10
0
2.7 3.0
3.5
4.0
4.5
RXEN = HIGH
5.0
5.5
-150
-200
-250
200
300
RX OFF IMAGINARY
400
500
.2
0
0
0.4
0.8
1.2
1.6
2.0
TXEN = LOW
RXEN = HIGH
2.4 2.8
3.0
V CC (V)
FREQUENCY (MHz)
GC VOLTAGE (V)
6
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