UG-570
AD9361 Reference Manual
| Page 48 of 128
Table 32 shows a small portion of an example full gain table. This
is the same format as the Analog Devices supplied full gain table,
but some of the columns are color-coded to aid in the clarity of
the column purposes. It is important to note that the BBP only
uses the values in the table index column as well as the 0x131,
0x132, 0x133 columns when programming a gain table into the
AD9361
. These 0x131, 0x132, 0x133 columns have register
addresses as column headers. The 0x131, 0x132, 0x133 columns
are concatenations of various gain stage indices. For example,
0x131 is a digital word that includes the gain indices for the
external LNA, the internal LNA, and the mixer. All other columns
are only used to make the gain table more readable.
Starting at the far left of Table 32, table index is the index or
pointer to the table. When the
AD9361
is in the FDD or receive
states, this index controls the receive path gain.
The next column to the right is the external LNA index. See the
External LNA section for details on how the
AD9361
can control
an external LNA. Briefly, a bit in the gain table can be output to a
GPO and used to control the gain of an external LNA.
The next column to the right is the external LNA gain. This
column has no purpose except to indicate total receive path gain
when using an external LNA.
Moving to the right again leads to the iLNA index. This is the
internal LNA index, which controls LNA gain. iLNA Gain in dB is
next to iLNA index which is only used to add to other stages gains
and which result in the estimated total receive path gain.
Again moving to the right results in the mixer index and next to
that column is the mixer gain, both of which are analogous to the
iLNA index and iLNA gain described previously.
The 0x131 column to the right is the digital word that is a
concatenation of all of the previous indices.
The TIA index and TIA gain are related as described previously
for other gain stages. The LPF index is always equal to the LPF
gain in dB so only the index column is shown. 0x132 is a
concatenation of the TIA and LPF indices.
The RF DC Cal bit is described in the RF DC Cal Bit section.
Digital gain, like the LPF gain, is equal to the digital index so only
the index column is shown. 0x133 is a concatenation of the DC
Cal bit and the digital index.
Finally, the total gain column shows the estimated total Rx path
gain of the
AD9361
for each gain index.
Table 32. Portion of Analog Devices 800 MHz Full Gain Table
Table
Index
eLNA
Index
eLNA
Gain
iLNA
Index
iLNA
Gain
Mixer
Index
Mixer
Gain
0x131
TIA
Index
TIA
Gain
LPF
Index 0x132
DC
Cal
Digital
Index
0x133
Total
Gain
0
0
0
0
5
0
0
0
0
−6
0
0
1
0
20
−1
1
0
0
0
5
0
0
0
0
−6
0
0
0
0
0
−1
2
0
0
0
5
0
0
0
0
−6
0
0
0
0
0
−1
3
0
0
0
5
0
0
0
0
−6
1
1
0
0
0
0
4
0
0
0
5
0
0
0
0
−6
2
2
0
0
0
1
5
0
0
0
5
0
0
0
0
−6
3
3
0
0
0
2
6
0
0
0
5
0
0
0
0
−6
4
4
0
0
0
3
7
0
0
0
5
0
0
0
0
−6
5
5
0
0
0
4
8
0
0
0
5
1
3
1
0
−6
3
3
1
0
20
5
9
0
0
0
5
1
3
1
0
−6
4
4
0
0
0
6
10
0
0
0
5
1
3
1
0
−6
5
5
0
0
0
7
11
0
0
0
5
1
3
1
0
−6
6
6
0
0
0
8
12
0
0
0
5
1
3
1
0
−6
7
7
0
0
0
9
13
0
0
0
5
1
3
1
0
−6
8
8
0
0
0
10
Rev. A
