Ds1875, Pon triplexer and sfp controller – Rainbow Electronics DS1875 User Manual
Page 85
DS1875
Table 02h, Register FBh to FCh: BIAS DAC
FACTORY
DEFAULT
8000h
READ
ACCESS
PW2
WRITE
ACCESS
N/A
MEMORY
TYPE
Volatile
FBh BOL
0
2
12
2
11
2
10
2
9
2
8
2
7
FCh 2
7
2
6
2
5
2
4
2
3
2
2
2
1
2
0
BIT
7
BIT
0
The bias open-loop bit (BOL) reflects the status of the BIAS current-control loop. If it is 1, the loop is open and
the DS1875 is controlling the BIAS output from the LUT. If it is 0, the loop is closed and the BIAS output is
controlled by active feedback from the BMD pin. The remaining bits are the digital value used for the BIAS
output regardless of the value of OL.
Table 02h, Register FDh: BIAS OL
FACTORY
DEFAULT
00h
READ
ACCESS PW2
WRITE ACCESS
PW2 and APC EN = 1
MEMORY TYPE
Volatile
FDh 2
7
2
6
2
5
2
4
2
3
2
2
2
1
2
0
BIT
7
BIT
0
The digital value used for BIAS at power-on and during open loop. It is recalled from Table 08h at the adjusted
memory address found in TINDEX. This register is updated at the end of the temperature conversion. The
correct value depends on the value of BOLFS (Table 02h, Register 89h, bit 3).
If BOLFS = 0, BIAS OL[7:0] = I
BIAS
[11:4].
If BOLFS = 1, BIAS OL[7:0] = I
BIAS
[12:5].
PON Triplexer and SFP Controller
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