AT86RF212B_14 Datasheet, PDF (149/212 Pages) ATMEL Corporation – Fully integrated 769 – 935MHz transceiver including

AT86RF212B
Table 9-34 shows the settings of CC_BAND and CC_NUMBER.
Table 9-34. Frequency Bands and Numbers.
CC_BAND CC_NUMBER Description
0
Not used
European and North American channels according to
IEEE 802.15.4; Frequency selected by register bits CHANNEL
(register 0x08, PHY_CC_CCA), refer to Section 9.8.6
1
0x00 – 0xFF 769.0MHz – 794.5MHz
Fc [MHz] = 769.0[MHz] + 0.1[MHz] x CC_NUMBER
2
0x00 – 0xFF 857.0MHz – 882.5MHz
Fc [MHz] = 857.0[MHz] + 0.1[MHz] x CC_NUMBER
3
0x00 – 0xFF 903.0MHz – 928.5MHz
Fc [MHz] = 903.0[MHz] + 0.1[MHz] x CC_NUMBER
4
0x00 – 0x5E 769MHz – 863MHz
Fc [MHz] = 769[MHz] + 1[MHz] x CC_NUMBER
5
0x00 – 0x66 833MHz – 935MHz
Fc [MHz] = 833[MHz] + 1[MHz] x CC_NUMBER
6
0x00 – 0xFF 902.0MHz – 927.5MHz
Fc [MHz] = 902.0[MHz] + 0.1[MHz] x CC_NUMBER
7
0x00 – 0xFF Reserved
9.8.3 PLL Settling Time and Frequency Agility
When the PLL is enabled during state transition from TRX_OFF to PLL_ON or RX_ON,
the settling time is typically t_TR4 = 170µs, including PLL self calibration. For more
information, refer to Table 7-2 and Section 9.8.4. A lock of the PLL is indicated with an
interrupt IRQ_0 (PLL_LOCK).
Switching between channels within a frequency band in PLL_ON or RX_ON states is
typically done within t_{PLL_SW} = 11µs. This makes the radio transceiver highly suitable for
frequency hopping applications.
The PLL frequency in PLL_ON and receive states is 1MHz below the PLL frequency in
transmit states. When starting the transmit procedure, the PLL frequency is changed to
the transmit frequency within a period of t_{RX_TX} = 16µs before really starting the
transmission. After the transmission, the PLL settles back to the receive frequency
within a period of t_{TX_RX} = 32µs. This frequency step does not generate an interrupt
IRQ_0 (PLL_LOCK) or IRQ_1 (PLL_UNLOCK) within these periods.
9.8.4 Calibration Loops
Due to variation of temperature, supply voltage and part-to-part variations of the radio
transceiver the VCO characteristics may vary.
To ensure a stable operation, two automated control loops are implemented, center
frequency (CF) tuning and delay cell (DCU) calibration. Both calibration loops are
initiated automatically when the PLL is enabled during state transition from TRX_OFF to
PLL_ON or RX_ON state. Additionally, both calibration loops are initiated when the PLL
changes to a different frequency setting.
If the PLL operates for a long time on the same channel, for example more than five
minutes, or the operating temperature changes significantly, it is recommended to
initiate the calibration loops manually.
Both Atmel AT86RF212B calibration loops can be initiated manually by SPI command.
To start the calibration, the device should be in state PLL_ON. The center frequency
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