Single-Chip Low Power RF Transceiver for Narrowband Systems ...

ANALOG Register (17h)
REGISTER NAME Default
value
Active Description
ANALOG[7] BANDSELECT 1 - Frequency band selection
0: 402-470 MHz band
1: 804-940 MHz band
ANALOG[6] LO_DC 1 - Lower LO DC level to mixers
0: High LO DC level to mixers
1: Low LO DC level to mixers
CC1021
Recommended settings:
LO_DC=1 for 402-470 MHz,
LO_DC=0 for 804-940 MHz.
ANALOG[5] VGA_BLANKING 1 H Enable analog blanking switches in VGA when
changing VGA gain.
0: Blanking switches are disabled
1: Blanking switches are turned on for approx.
0.8µs when gain is changed (always on if
AGC_DISABLE=1)
Recommended setting: VGA_BLANKING=0.
ANALOG[4] PD_LONG 0 H Selects short or long reset delay in phase
detector
0: Short reset delay
1: Long reset delay
Recommended setting: PD_LONG=0.
ANALOG[3] - 0 - Reserved, write 0
ANALOG[2] PA_BOOST 0 H Boost PA bias current for higher output power
ANALOG[1:0]
DIV_BUFF_CURRENT[1:0] 3 -
Recommended setting: PA_BOOST=1.
Overall bias current adjustment for VCO divider
and buffers
0: 4/6 of nominal VCO divider and buffer current
1: 4/5 of nominal VCO divider and buffer current
2: Nominal VCO divider and buffer current
3: 4/3 of nominal VCO divider and buffer current
Recommended setting:
DIV_BUFF_CURRENT=3
BUFF_SWING Register (18h)
REGISTER NAME Default
value
Active Description
BUFF_SWING[7:6] PRE_SWING[1:0] 3 - Prescaler swing. Fractions for PRE_CURRENT=0:
0: 2/3 of nominal swing
1: 1/2 of nominal swing
2: 4/3 of nominal swing
3: Nominal swing
Recommended setting: PRE_SWING=0
BUFF_SWING[5:3] RX_SWING[2:0] 4 - LO buffer swing, in RX (to mixers)
0: Smallest load resistance (smallest swing)
…
7: Largest load resistance (largest swing)
Recommended setting: RX_SWING=2.
BUFF_SWING[2:0] TX_SWING[2:0] 1 - LO buffer swing, in TX (to power amplifier driver)
0: Smallest load resistance (smallest swing)
…
7: Largest load resistance (largest swing)
Recommended settings:
TX_SWING=4 for 402-470 MHz,
TX_SWING=0 for 804-940 MHz.
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