Single-Chip Low Power RF Transceiver for Narrowband Systems ...
Single-Chip Low Power RF Transceiver for Narrowband Systems ...
Single-Chip Low Power RF Transceiver for Narrowband Systems ...
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f ref is the reference frequency (in<br />
MHz)<br />
Calibrate RX frequency register A<br />
(to calibrate TX frequency register<br />
B write MAIN register = D1h).<br />
Register CALIBRATE = 34h<br />
Start calibration<br />
Start single calibration<br />
Write FREQ_A, FREQ_B, VCO,<br />
CLOCK_A and CLOCK_B registers.<br />
PLL_BW = 174 + 16log 2 (f ref /7.126)<br />
Write MAIN register = 11h:<br />
RXTX=0, F_REG=0, PD_MODE=1,<br />
FS_PD=0, CORE_PD=0, BIAS_PD=0,<br />
RESET_N=1<br />
Write CALIBRATE register = B4h<br />
Wait <strong>for</strong> T≥100 us<br />
Read STATUS register and wait until<br />
CAL_COMPLETE=1<br />
Read STATUS register and wait until<br />
LOCK_CONTINUOUS=1<br />
Calibration OK?<br />
Yes<br />
End of calibration<br />
No<br />
Figure<br />
29. <strong>Single</strong> calibration algorithm <strong>for</strong> RX and TX<br />
15.3.<br />
PLL Turn-on Time versus Loop Filter Bandwidth<br />
CC1021<br />
If cal ibration has been per<strong>for</strong>med the PLL<br />
mode. The PLL turn-on time depends on<br />
turn-on time is the time needed <strong>for</strong> the PLL the PLL loop filter bandwidth. Table 25<br />
to lock to the desired frequency when gives the PLL turn-on time <strong>for</strong><br />
different<br />
going from power down mode (with the<br />
crystal oscillator running) to TX or RX<br />
PLL<br />
loop filter bandwidths.<br />
SWRS045B Page 52 of 89
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