TRF6900 Datasheet, PDF (24/34 Pages) Texas Instruments – SINGLE-CHIP RF TRANSCEIVER

TRF6900
SINGLE-CHIP RF TRANSCEIVER
SLAS213C – SEPTEMBER 1999 – REVISED MAY 2000
PRINCIPLES OF OPERATION
Table 1. Mode0 Control Register Description (D-Word)
SYMBOL
BIT
LOCATION
NUMBER
OF BITS
DESCRIPTION
INITIAL SETTINGS
AFTER POWER-UP
DEFAULT DEFAULT
STATE
VALUE
0_LNAM
[1:0]
Low-noise amplifier operation mode
Disabled
00b
L1
L0
2
0
0 : LNA disabled
0
1 : LNA enable – low-gain mode
1
0 : LNA disabled
1
1 : LNA enable – normal operation mode
0_MIX
[2]
0_IF
[3]
1
Enable mixer
1
Enable 1st IF amplifier
1: enabled
1: enabled
0: disabled
0: disabled
Disabled
0b
Disabled
0b
0_LIM
[4]
1
Enable limiter
1: enabled
0: disabled
Disabled
0b
0_RSSI
[5]
1
Enable RSSI
1: enabled
0: disabled
Disabled
0b
0_SW
[6]
1
Data switch
Routed to
0b
Demodulator
0 : LPF amplifier input routed to demodulator (FSK/FM)
1 : LPF amplifier input routed to RSSI (OOK/ASK)
0_LPF
[7]
1
Enable LPF amplifier
1: enabled
0: disabled
Disabled
0b
0_SLC
[8]
1
Enable data slicer
1: enabled
0: disabled
Disabled
0b
0_PA
[10:9]
Power amplifier mode
Disabled
00b
P1 P0
2
0 0 : disabled
0 1 : 10 dB attenuation, enable modulation via TX_DATA
1 0 : 20 dB attenuation, enable modulation via TX_DATA
1 1 : 0 dB attenuation, enable modulation via TX_DATA
0_VCO
[11]
1
During operation, this bit should always be enabled (1: enabled), unless
an external VCO is used.
Disabled
0b
0_PLL
[12]
Enable PLL (DDS system, RF, VCO, divider, phase comparator and charge Disabled
0b
1
pump)
1: enabled
0: disabled
NOTE: The FM/FSK demodulator is automatically enabled if the limiter and low-pass amplifier are enabled and the data switch is set to FSK
reception.
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