DS1874T+ Maxim Integrated Products, DS1874T+ Datasheet - Page 68

• 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 BAh: RESERVED
SFP+ Controller with Digital LDD Interface
Table 02h, Register BBh: ISTEP
Table 02h, Register BCh: HTXP
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BBh
BCh
FACTORY DEFAULT
READ ACCESS
WRITE ACCESS
MEMORY TYPE
This register is reserved.
FACTORY DEFAULT
READ ACCESS
WRITE ACCESS
MEMORY TYPE
The initial step value used at power-on or after a TXD pulse to control the BIAS register. At startup, this value plus
2
At that time, a binary search is used to complete the startup of the APC closed loop. If the resulting math operation is
greater than IBIASMAX (Table 02h, Register EEh), the result is not loaded into the BIAS register, but the binary
search is begun to complete the initial search for APC. During startup, the BIAS register steps causing a higher bias
value than IBIASMAX do not create the BIAS MAX alarm. The BIAS MAX alarm detection is enabled at the end of the
binary search.
FACTORY DEFAULT
READ ACCESS
WRITE ACCESS
MEMORY TYPE
Fast-comparison DAC threshold adjust for high TXP. This value is added to the APC DAC value recalled from
Table 06h. If the sum is greater than 0xFF, 0xFF is used. Comparisons greater than V
V
0
MON2
= 1 is continuously added to the BIAS register value until the APC feedback (MON2) is greater than its threshold.
BIT 7
BIT 7
2
2
8
7
, create a TXP HI alarm. The same ranging applied to the APC DAC should be used here.
2
2
7
6
00h
PW2 or (PW1 and RWTBL246) or (PW1 and RTBL246)
PW2 or (PW1 and RWTBL246)
Nonvolatile (SEE)
00h
PW2 or (PW1 and RWTBL246) or (PW1 and RTBL246)
PW2 or (PW1 and RWTBL246)
Nonvolatile (SEE)
00h
PW2 or (PW1 and RWTBL246) or (PW1 and RTBL246)
PW2 or (PW1 and RWTBL246)
Nonvolatile (SEE)
2
2
6
5
V
HTXP
=
Full Scale
2
255
2
5
4
(
HTXP + APC DAC
2
2
4
3
)
2
2
3
2
HTXP
2
2
2
1
, compared against
BIT 0
BIT 0
2
2
1
0