DS1874T+ Maxim Integrated Products, DS1874T+ Datasheet - Page 84

• Manufacturer Part Number: DS1874T+
• Description: IC CTLR SFP+ ANLG LDD 28-TQFN
• Manufacturer: Maxim Integrated Products
• Type: Laser Diode Controllerr

Specifications of DS1874T+

• 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
• Number Of Outputs: 5
• Duty Cycle (max): 50 %
• Output Voltage: 0 V to 3.9 V
• Mounting Style: SMD/SMT
• Switching Frequency: 0 KHz to 400 KHz
• Operating Supply Voltage: 2.85 V to 3.9 V
• Supply Current: 2.5 mA to 10 mA
• Maximum Operating Temperature: + 95 C
• Fall Time: 300 ns
• Minimum Operating Temperature: - 40 C
• Rise Time: 300 ns
• Synchronous Pin: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 90-1874T+000

Table 02h, Register FDh: TXSTAT2
SFP+ Controller with Digital LDD Interface
Table 02h, Register FEh–FFh: RESERVED
Table 04h, Register 80h–C7h: MODULATION LUT
84
80h–C7h
______________________________________________________________________________________
FDh
FACTORY DEFAULT
READ ACCESS
WRITE ACCESS
MEMORY TYPE
These registers are reserved.
FACTORY DEFAULT
READ ACCESS
WRITE ACCESS
MEMORY TYPE
MAX3798/MAX3799 register. This value is read from the MAX3798/MAX3799 with the 3-wire interface every t
(see the MAX3798/MAX3799 electrical characteristics).
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 MODULATION
REGISTER. 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
MODULATION REGISTER (Table 02h, Register 82h–83h) location that holds the value until the next temperature
conversion. The DS1874 can be placed into a manual mode (MOD EN bit, Table 02h, Register 80h), where the
MODULATION REGISTER is directly controlled for calibration. If the temperature compensation functionality is
not required, then program the entire Table 04h to the desired modulation setting.
BIT 7
BIT 7
2
2
7
7
2
2
6
6
00h
PW2 or (PW1 and RWTBL246) or (PW1 and RTBL246)
PW2 or (PW1 and RWTBL246)
Nonvolatile (EE)
00h
Volatile
00h
PW2 or (PW1 and RWTBL246) or (PW1 and RTBL246)
N/A
Volatile
PW2 or (PW1 and RWTBL246) or (PW1 and RTBL246)
PW2 or (PW1 and RWTBL246)
2
2
5
5
2
2
4
4
2
2
3
3
Table 04h Register Description
2
2
2
2
2
2
1
1
BIT 0
BIT 0
2
2
0
0
RR