SA58646 Datasheet, PDF (16/42 Pages) NXP Semiconductors – UHF 900 MHz transceiver IC

NXP Semiconductors
SA58646
UHF 900 MHz transceiver IC
8.1 Data register 0
Table 8. Data register 0 (address 000h) bit description
Legend: * reset value.
Bit
Symbol
Value Description
15
SBS
Side band select. The image reject mixer can be
programmed to either reject the image frequency at the
LO upper frequency or at the LO lower frequency. It
enables the user to have the RX LO in or out of ISM
band and to use the same IC in both handset and base.
0*
frequency LO − IF is rejected
1
frequency LO + IF is rejected
14 to 13 EARP_VOL[1:0]
Earpiece volume control. Software gain control on the
earpiece amplifier is done with integrated switch
feedback resistances.
12
EARP
00
R_fbck = 14 kΩ, G_ctrl = 0 dB
01
R_fbck = 24 kΩ, G_ctrl = 4.7 dB
10
R_fbck = 41 kΩ, G_ctrl = 9.3 dB
11*
R_fbck = 70.2 kΩ, G_ctrl = 14 dB
Earpiece
0*
earpiece disable
1
earpiece enable; can be used in RX mode for specific
feature
11 to 7 RX_GAIN[4:0]
RX gain setting
0 1111* for values, see Table 9
6
SFS
Second filter select. Depending on the features of the
IF filters used, the user might not need to use the
second IF filter. IF filters having 4.5 dB insertion loss are
recommended.
0
second IF filter not selected
1*
second IF filter selected
5
D_PHASE
Data phase shifter. The SBS bit is used to invert the
phase of the data. Depending on the SBS bit value and
the protocol chosen, the data can be inverted between
the base and handset data transmission. To correct the
data polarity, bit D_PHASE is set.
0*
inverter is bypassed
1
inverter is used
4 to 0 FM_PLL_VCO[4:0]
PLL center frequency calibration. This programming
allows calibration of the center frequency of the VCO
within the FM PLL to align the frequency as close as
possible to the nominal 10.7 MHz frequency.
0 1111* For values, see Table 10
SA58646_1
Product data sheet
Rev. 01 — 8 February 2007
© NXP B.V. 2007. All rights reserved.
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