300MHz-to-450MHz Low-Power, Crystal-Based

ASK Transmitter

_______________________________________________________________________________________

5

TRANSMIT POWER EFFICIENCY

vs. SUPPLY VOLTAGE

SUPPLY VOLTAGE (V)

3.2

2.8

2.4

30

35

40

45

50

25

2.0

3.6

-40

°C

+25

°C

+85

°C

+125

°C

CW OUTPUT

TRANSMIT POWER EFFICIENCY

vs. SUPPLY VOLTAGE

SUPPLY VOLTAGE (V)

3.2

2.8

2.4

20

25

30

35

40

45

50

2.0

3.6

-40

°C

+25

°C

+85

°C

+125

°C

OOK OUTPUT AT

50% DUTY CYCLE

TRANSMIT POWER EFFICIENCY

vs. SUPPLY VOLTAGE

SUPPLY VOLTAGE (V)

3.2

2.4

2.8

25

30

35

40

45

20

2.0

3.6

-40

°C

+25

°C

+85

°C

+125

°C

OOK OUTPUT AT

50% DUTY CYCLE

PHASE NOISE vs. OFFSET FREQUENCY

1M

100k

10k

1k

100

-130

-120

-110

-100

-90

-80

-70

-60

-50

-40

-140

10

10M

SUPPLY CURRENT AND OUTPUT POWER

vs. EXTERNAL RESISTOR

MAX1472 toc14

EXTERNAL RESISTOR (

Ω)

100

10

1

2

4

6

8

10

12

0

0.1

1000

2

4

6

8

10

12

0

POWER

CURRENT

SUPPLY CURRENT vs. OUTPUT POWER

OUTPUT POWER (dBm)

8

6

2

4

3

4

5

6

7

8

9

10

2

010

50% DUTY CYCLE

CW

FREQUENCY SETTLING TIME

MAX1472 toc16

25kHz/div

ENABLE

TRANSITION

FROM LOW

TO HIGH

ENABLE

TRANSITION

FROM LOW

TO HIGH

2.5kHz/div

START: 0s

START: 0s

1ms

1ms

Typical Operating Characteristics (continued)

AM DEMODULATION OF PA OUTPUT

MAX1472 toc17

DATA RATE

= 100kHz

START: 0s

STOP: 20

µs

15%/div