SWRS046H – NOVEMBER 2006 – REVISED MARCH 2015
Table 5-43. BUFF_CURRENT Register (19h)
DEFAULT
REGISTER
NAME
ACTIVE
DESCRIPTION
VALUE
BUFF_CURRENT[7:6]
PRE_CURRENT[1:0]
1
—
Prescaler current scaling
0: Nominal current
1: 2/3 of nominal current
2: 1/2 of nominal current
3: 2/5 of nominal current
Recommended setting: PRE_CURRENT=0.
BUFF_CURRENT[5:3]
RX_CURRENT[2:0]
4
—
LO buffer current, in RX (to mixers)
0: Minimum buffer current
…
7: Maximum buffer current
Recommended setting: RX_CURRENT=4.
BUFF_CURRENT[2:0]
TX_CURRENT[2:0]
5
—
LO buffer current, in TX (to PA driver)
0: Minimum buffer current
…
7: Maximum buffer current
Recommended settings:
TX_CURRENT=2 for 402 to 470 MHz,
TX_CURRENT=5 for 804 to 960 MHz.
Table 5-44. PLL_BW Register (1Ah)
DEFAULT
REGISTER
NAME
ACTIVE
DESCRIPTION
VALUE
PLL_BW[7:0]
PLL_BW[7:0]
134
—
Charge pump current scaling/rounding factor. Used to calibrate charge
pump current for the desired PLL loop bandwidth.
The value is given by:
PLL_BW = 174 + 16 log
2
(f
ref
/ 7.126)
where f
ref
is the reference frequency in MHz.
Table 5-45. CALIBRATE Register (1Bh)
DEFAULT
REGISTER
NAME
ACTIVE
DESCRIPTION
VALUE
CALIBRATE[7]
CAL_START
0
↑
↑
1: Calibration started
0: Calibration inactive
CALIBRATE[6]
CAL_DUAL
0
H
Use calibration results for both frequency A and B
0: Store results in A or B defined by F_REG (MAIN[6])
1: Store calibration results in both A and B
CALIBRATE[5:4]
CAL_WAIT[1:0]
0
—
Selects calibration wait time (affects accuracy)
0 (00): Calibration time is approx. 90000 F_REF periods
1 (01): Calibration time is approx. 110000 F_REF periods
2 (10): Calibration time is approx. 130000 F_REF periods
3 (11): Calibration time is approx. 200000 F_REF periods
Recommended setting: CAL_WAIT=3 for best accuracy in calibrated
PLL loop filter bandwidth.
CALIBRATE[3]
—
0
—
Reserved, write 0
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Detailed Description
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