
Low-Cost, Crystal-Based, Programmable,
ASK/FSK Transceiver with Fractional-N PLL
Typical Operating Characteristics (continued)
(Typical Application Circuit, V PAVDD = V AVDD = V DVDD = V HVIN = +3.0V, f RF = 433.92MHz, T A = +25°C, IF BW = 280kHz, data rate
= 4kbps Manchester encoded, frequency deviation = ±50kHz, BER = 0.2% average RF power, unless otherwise noted.)
TRANSMITTER
EFFICIENCY vs. SUPPLY VOLTAGE
EFFICIENCY vs. SUPPLY VOLTAGE
PHASE NOISE vs. OFFSET FREQUENCY
30
25
f RF = 315MHz
50% DUTY CYCLE
T A = -40 ° C
T A = +25 ° C
30
25
f RF = 434MHz
50% DUTY CYCLE
T A = -40 ° C
T A = +25 ° C
-40
-50
-60
-70
-80
f RF = 315MHz
20
-90
15
T A = +85 ° C
T A = +125 ° C
20
T A = +85 ° C
-100
-110
-120
T A = +125 ° C
-130
10
15
-140
2.1
2.4
2.7
3.0
3.3
3.6
2.1
2.4
2.7
3.0
3.3
3.6
100
1k
10k
100k
1M
10M
SUPPLY VOLTAGE (V)
PHASE NOISE
vs. OFFSET FREQUENCY
SUPPLY VOLTAGE (V)
OFFSET FREQUENCY (Hz)
REFERENCE SPUR MAGNITUDE
vs. SUPPLY VOLTAGE
-40
-50
f RF = 434MHz
-40
-60
-70
-80
-90
-100
-110
-120
-130
-140
-45
-50
-55
-60
-65
-70
433.92MHz
315MHz
100
1k
10k
100k
1M
10M
2.1
2.4
2.7
3.0
3.3
3.6
OFFSET FREQUENCY (Hz)
FREQUENCY STABILITY
vs. SUPPLY VOLTAGE
SUPPLY VOLTAGE (V)
CLKOUT SPUR MAGNITUDE
vs. SUPPLY VOLTAGE
10
8
-56
f RF = 434MHz
CLKOUT SPUR = f RF ± f CLKOUT
6
4
2
0
-2
-4
f RF = 315MHz
f RF = 434MHz
-58
-60
-62
10pF LOAD CAPACITANCE
f CLKOUT = f XTAL /8
f CLKOUT = f XTAL /2
-6
-8
-10
-64
-66
f CLKOUT = f XTAL /4
2.1
2.4
2.7
3.0
3.3
3.6
2.1
2.4
2.7
3.0
3.3
3.6
SUPPLY VOLTAGE (V)
SUPPLY VOLTAGE (V)
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11