RF6001_1 RFMD [RF Micro Devices], RF6001_1 Datasheet - Page 37

• Manufacturer Part Number: RF6001_1
• Description: FRACTIONAL-N RF SYNTHESIZER WITH MODULATOR AND DIGITAL IF FILTER
• Manufacturer: RFMD [RF Micro Devices]

Analog I/Q Mode
Programming the TXAD bit low puts the GMSK modulation interface in analog mode.
In this mode, programmable comparators are used to determine the symbols contained in the I and Q baseband waveforms at
each symbol time.
The positive and negative thresholds used for the differential I and Q channel comparison are set by SDI bits TX_THP[3:0] and
TX_THN[3:0] according to the following formulae.
Each threshold should be set as close as possible to 0.625 times the peak differential I or Q voltage.
The following table indicates the appropriate threshold SDI settings for a given peak voltage of modulation waveform from the
baseband.
Rev A3 DS050929
Baseband
V
PK
0.16
0.24
0.32
0.40
0.48
0.56
0.64
0.72
0.80
0.88
0.96
1.04
1.12
1.20
1.28
1.36
Vth (positive)=0.05*(TX_THP+2) where TX_THP is the value between 0 and 15 that is programmed into that reg-
ister.
Vth (negative)=-0.05*(TX_THN+2) where TX_THN is the value between 0 and 15 that is programmed into that register.
(V)
from
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0.45
0.50
0.55
0.60
0.65
0.70
0.75
0.80
0.85
Vth
(V)
Recommended Programming Value
TH_THP[3:0]
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support, contact RFMD at ([phone] or [e-mail].
First Bit into
10
11
12
13
14
15
Modulator
PA Ramp
0
1
2
3
4
5
6
7
8
9
TX_EN
TX_ST
TH_THN[3:0]
12
10
11
13
14
15
0
1
2
3
4
5
6
7
8
9
TXENU
Transmission of Data from the FIFO
PAT
MD_DLY
Part of the POLARIS™ TOTAL RADIO™ Solution
RF6001
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