DS1874T+ Maxim Integrated Products, DS1874T+ Datasheet - Page 55

• 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 80h: MODE
80h
SFP+ Controller with Digital LDD Interface
POWER-ON VALUE
READ ACCESS
WRITE ACCESS
MEMORY TYPE
SEEB
BIT 7
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
______________________________________________________________________________________
SEEB:
0 = (Default) Enables EEPROM writes to SEE bytes.
1 = Disables EEPROM writes to SEE bytes during configuration, so that the configuration of the part
is not delayed by the EE cycle time. Once the values are known, write this bit to a 0 and write the
SEE locations again for data to be written to the EEPROM.
RESERVED
DAC1 EN:
0 = DAC1 VALUE is writable by the user and the LUT recalls are disabled. This allows users to
interactively test their modules by writing the values for DAC1. The output is updated with the new
value at the end of the write cycle. The I
1 = (Default) Enables auto control of the LUT for DAC1 VALUE.
DAC2 EN:
0 = DAC2 VALUE is writable by the user and the LUT recalls are disabled. This allows users to
interactively test their modules by writing the values for DAC2. The output is updated with the new
value at the end of the write cycle. The I
1 = (Default) Enables auto control of the LUT for DAC2 VALUE.
AEN:
0 = The temperature-calculated index value TINDEX is writable by users and the updates of
calculated indexes are disabled. This allows users to interactively test their modules by
controlling the indexing for the LUTs. The recalled values from the LUTs appear in the DAC
registers after the next completion of a temperature conversion.
MOD EN:
0 = Modulation is writable by the user and the LUT recalls are disabled. This allows users to
interactively test their modules by writing the DAC value for modulation. The output is updated with the
new value at the end of the write cycle. The I
1 = (Default) Enables auto control of the LUT for modulation.
APC EN:
0 = APC DAC is writable by the user and the LUT recalls are disabled. This allows users to
interactively test their modules by writing the DAC value for APC reference. The output is updated with
the new value at the end of the write cycle through the 3-wire interface. The I
end of the write cycle.
1 = (Default) Enables auto control of the LUT for APC reference.
BIAS EN:
0 = BIAS register is controlled by the user and the APC is in manual mode. The BIAS register value
is written with the use of the 3-wire interface. This allows the user to interactively test their modules
by writing the DAC value for bias.
1 = (Default) Enables auto control for the APC feedback.
RESERVED
3Fh
PW2 or (PW1 and RWTBL246) or (PW1 and RTBL246)
PW2 or (PW1 and RTBL246)
Volatile
DAC1 EN
DAC2 EN
2
C STOP condition is the end of the write cycle.
2
C STOP condition is the end of the write cycle.
2
C STOP condition is the end of the write cycle.
AEN
Table 02h Register Descriptions
MOD EN
APC EN
2
C STOP condition is the
BIAS EN
BIT 0
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