CC2550_13 Datasheet, PDF (48/61 Pages) Texas Instruments – Low-Cost Low-Power 2.4 GHz RF Transmitter

CC2550
0x23: FSCAL3 – Frequency Synthesizer Calibration
Bit Field Name
Reset R/W Description
7:6 FSCAL3[7:6]
5:4 CHP_CURR_CAL_EN[1:0]
3:0 FSCAL3[3:0]
2 (10)
2 (10)
9
(1001)
R/W
R/W
R/W
Frequency synthesizer calibration configuration. The value to write
in this register before calibration is given by the SmartRF^® Studio
software [4].
Disable charge pump calibration stage when 0
Frequency synthesizer calibration result register. Digital bit vector
defining the charge pump output current, on an exponential scale:
IOUT=I₀·2^{FSCAL3[3:0]/4}
Fast frequency hopping without calibration for each hop can be
done by calibrating upfront for each frequency and saving the
resulting FSCAL3, FSCAL2 and FSCAL1 register values. Between
each frequency hop, calibration can be replaced by writing the
FSCAL3, FSCAL2 and FSCAL1 register values corresponding to
the next RF frequency.
0x24: FSCAL2 – Frequency Synthesizer Calibration
Bit Field Name
Reset R/W Description
7:6 Reserved
5 VCO_CORE_H_EN
4:0 FSCAL2[5:0]
R0
0
R/W
10
R/W
(0x0A)
Choose high (1) / low (0) VCO
Frequency synthesizer calibration result register. VCO current
calibration result and override value
Fast frequency hopping without calibration for each hop can be
done by calibrating upfront for each frequency and saving the
resulting FSCAL3, FSCAL2 and FSCAL1 register values. Between
each frequency hop, calibration can be replaced by writing the
FSCAL3, FSCAL2 and FSCAL1 register values corresponding to
the next RF frequency.
Bit Field Name
7:6 Reserved
5:0 FSCAL1[5:0]
0x25: FSCAL1 – Frequency Synthesizer Calibration
Reset R/W Description
R0
32
R/W Frequency synthesizer calibration result register. Capacitor array
(0x20)
setting for VCO coarse tuning.
Fast frequency hopping without calibration for each hop can be
done by calibrating upfront for each frequency and saving the
resulting FSCAL3, FSCAL2 and FSCAL1 register values. Between
each frequency hop, calibration can be replaced by writing the
FSCAL3, FSCAL2 and FSCAL1 register values corresponding to
the next RF frequency.
Bit Field Name
7 Reserved
6:5 Reserved
4:0 FSCAL0[4:0]
0x26: FSCAL0 – Frequency Synthesizer Calibration
Reset R/W Description
0 (00)
13
(0x0D)
R0
R0
R/W
Defined in the transceiver version
Frequency synthesizer calibration control. The value to use in
register field is given by the SmartRF^® Studio software [4].
SWRS039B
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