DS1874T+ Maxim Integrated Products, DS1874T+ Datasheet - Page 56

• 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

SFP+ Controller with Digital LDD Interface
Table 02h, Register 81h: Temperature Index (TINDEX)
Table 02h, Register 82h–83h: MODULATION REGISTER
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81h
82h
83h
FACTORY DEFAULT
READ ACCESS
WRITE ACCESS
MEMORY TYPE
Holds the calculated index based on the temperature measurement. This index is used for the address during
lookup of Tables 04h, 06h–08h. Temperature measurements below -40°C or above +102°C are clamped to 08h and
C7h, respectively. The calculation of TINDEX is as follows:
For the temperature-indexed LUTs, the index used during the lookup function for each table is as follows:
FACTORY DEFAULT
READ ACCESS
WRITE ACCESS
MEMORY TYPE
The digital value used for MODULATION and recalled from Table 04h at the adjusted memory address found in
TINDEX. This register is updated at the end of the temperature conversion.
Table 04h (MOD)
Table 06h (APC)
Table 07h (DAC1)
Table 08h (DAC2)
BIT 7
BIT 7
2
2
0
7
7
2
2
0
6
6
1
1
1
1
TINDEX
00h
PW2 or (PW1 and RWTBL246) or (PW1 and RTBL246)
(PW2 and AEN = 0) or (PW1 and RWTBL246 and AEN = 0)
Volatile
0000h
PW2 or (PW1 and RWTBL246) or (PW1 and RTBL246)
(PW2 and MOD EN = 0) or (PW1 and RWTBL246 and MOD EN = 0)
Volatile
0
0
0
2
2
0
6
5
5
TINDEX =
TINDEX
TINDEX
TINDEX
TINDEX
5
6
6
6
2
2
0
Temp _ Value + 40°C
4
4
TINDEX
TINDEX
TINDEX
TINDEX
2°C
4
5
5
5
2
2
0
3
3
TINDEX
TINDEX
TINDEX
TINDEX
+ 80h
3
4
4
4
2
2
TINDEX
TINDEX
TINDEX
TINDEX
0
2
2
2
3
3
3
TINDEX
TINDEX
TINDEX
TINDEX
2
2
0
1
1
1
2
2
2
TINDEX
TINDEX
TINDEX
TINDEX
BIT 0
BIT 0
2
2
2
0
8
0
0
1
1
1