PLL Tuned UHF Transmitter for Data Transfer Applications, Rev. 2

Freescale Semiconductor

2

Table of Contents

1

Transmitter Functional Description . . . . . . . . . . . . . . . . . . . . . .4

2

Phase Locked Loop and Local Oscillator . . . . . . . . . . . . . . . . .4

3

RF Output Stage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

4

Modulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

5

Microcontroller Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

6

State Machine. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

7

Power Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

8

Data Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

9

Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

10 Radio Frequency (RF) Output Spectrum . . . . . . . . . . . . . . . .11

11 Output Power Measurement . . . . . . . . . . . . . . . . . . . . . . . . . .14

12 Complete Application Schematic and

PCB for OOK Modulation . . . . . . . . . . . . . . . . . . . . . . . . . . . .15

13 Complete Application Schematic and

PCB for FSK Modulation. . . . . . . . . . . . . . . . . . . . . . . . . . . . .17

14 Recommendations for FSK Modulation . . . . . . . . . . . . . . . . .19

15 Case Outline Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . .21

List of Figures

Figure 1. Simplified Block Diagram . . . . . . . . . . . . . . . . . . . . . . . 3

Figure 2. Crystal Pulling Configurations. . . . . . . . . . . . . . . . . . . . 5

Figure 3. State machine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Figure 4. Signals Waveform and Timing Definition . . . . . . . . . . . 7

Figure 5. RF Spectrum at 434 MHz Frequency Band

Displayed with a 5 MHz Span . . . . . . . . . . . . . . . . . . . 11

Figure 6. RF Spectrum at 434 MHz Frequency Band

Displayed with a 50 MHz Span . . . . . . . . . . . . . . . . . . 11

Figure 7. RF Spectrum at 434 MHz Frequency Band

Displayed with a 1.5 GHz Span . . . . . . . . . . . . . . . . . 12

Figure 8. RF Spectrum at 434 MHz Band

for a 70 kHz FSK Deviation at 4.8 kbit/s . . . . . . . . . . . 12

Figure 9. Output Power Measurement Configurations . . . . . . . . 13

Figure 10.Output Model and Matching Network

for 434 MHz Band . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Figure 11.Output Power at 434 MHz Band vs Rext Value . . . . . 14

Figure 12.Application Schematic for OOK Modulation,

434 MHz Frequency Band . . . . . . . . . . . . . . . . . . . . . . 15

Figure 13.Two-Button Keyfob Board Layout . . . . . . . . . . . . . . . . 16

Figure 14.Application Schematic for FSK Modulation,

Serial Configuration, 434 MHz Frequency Band . . . . . 17

Figure 15.Application PCB Layout for FSK Modulation,

Serial Configuration, 434 MHz Frequency Band . . . . . 18

Figure 16.Crystal Load Capacitance Contributors Schematic . . 19

Figure 17.Case Outline Dimensions . . . . . . . . . . . . . . . . . . . . . 20

List of Tables

Table 1. Pin Function Description . . . . . . . . . . . . . . . . . . . . . . . . 3

Table 2. Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . 3

Table 3. Band Selection and Associated Divider Ratios . . . . . . . 4

Table 4. DATACLK Frequency vs Crystal Oscillator Frequency. . 5

Table 5. Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . 8

Table 6. External Components Description for OOK. . . . . . . . . 15

Table 7. Typical Crystal Characteristics (SMD Package) . . . . . 16

Table 8. External Components Description for FSK . . . . . . . . . 17

Table 9. Crystal Pulling Capacitor Values vs

Carrier Frequency Total Deviation -1- . . . . . . . . . . . . . 18

Table 10.Crystal Pulling Capacitor Values vs

Carrier Frequency Total Deviation -2- . . . . . . . . . . . . . 18

Table 11.Pads and Tracks Parasitic Values . . . . . . . . . . . . . . . . 19