DS1873T+ Maxim Integrated Products, DS1873T+ Datasheet - Page 79

• Manufacturer Part Number: DS1873T+
• Description: IC CTLR SFP+ ANLG LDD 28-TQFN
• Manufacturer: Maxim Integrated Products
• Type: Laser Diode Controllerr

Specifications of DS1873T+

• Number Of Channels: 1
• Voltage - Supply: 2.85 V ~ 3.9 V
• Current - Supply: 2.5mA
• Operating Temperature: -40°C ~ 95°C
• Package / Case: 28-WFQFN Exposed Pad
• Mounting Type: Surface Mount
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 90-1873T+000

Table 04h, Register F8h–FFh: MOD OFFSET LUT
Table 04h, Register 80h–C7h: MODULATION LUT
80h–C7h
F8h–FFh
SFP+ Controller with Analog LDD Interface
FACTORY DEFAULT
READ ACCESS
WRITE ACCESS
MEMORY TYPE
FACTORY DEFAULT
READ ACCESS
WRITE ACCESS
MEMORY TYPE
The digital value for the modulation DAC output.
The MODULATION LUT is a set of registers assigned to hold the temperature profile for the MOD DAC. The
values in this table determine the set point for the modulation voltage. The temperature measurement is used to
index the LUT (TINDEX, Table 02h, Register 81h) in 2°C increments from -40°C to +102°C, starting at 80h in
Table 04h. Register 80h defines the -40°C to -38°C MOD output, Register 81h defines the -38°C to -36°C MOD
output, and so on. Values recalled from this EEPROM memory table are written into the MOD DAC (Table 02h,
Register 82h–83h) location that holds the value until the next temperature conversion. The DS1873 can be
placed into a manual mode (MOD EN bit, Table 02h, Register 80h), where the MOD DAC is directly controlled for
calibration. If the temperature compensation functionality is not required, then program the entire Table 04h to the
desired modulation setting.
The digital value for the temperature offset of the MOD DAC output.
The MOD DAC is a 10-bit register. The MODULATION LUT is an 8-bit LUT. The MOD OFFSET LUT times 4 plus
the MODULATION LUT makes use of the entire 10-bit range.
F8h
F9h
FAh
FBh
FCh
FDh
FEh
FFh
BIT 7
BIT 7
______________________________________________________________________________________
2
2
9
7
Less than or equal to -8°C
Greater than -8°C up to +8°C
Greater than +8°C up to +24°C
Greater than +24°C up to +40°C
Greater than +40°C up to +56°C
Greater than +56°C up to +72°C
Greater than +72°C up to +88°C
Greater than +88°C
2
2
6
8
00h
PW2 or (PW1 and RWTBL46) or (PW1 and RTBL46)
PW2 or (PW1 and RWTBL46)
Nonvolatile (EE)
00h
PW2 or (PW1 and RWTBL46) or (PW1 and RTBL46)
PW2 or (PW1 and RWTBL46)
Nonvolatile (EE)
2
2
5
7
2
2
4
6
2
2
3
5
Table 04h Register Description
2
2
2
4
2
2
1
3
BIT 0
BIT 0
2
2
0
2
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