DS1874T+ Maxim Integrated Products, DS1874T+ Datasheet - Page 69

• 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 BDh: LTXP
Table 02h, Register BEh: HLOS
Table 02h, Register BFh: LLOS
BDh
BEh
BFh
SFP+ Controller with Digital LDD Interface
FACTORY DEFAULT
READ ACCESS
WRITE ACCESS
MEMORY TYPE
FACTORY DEFAULT
READ ACCESS
WRITE ACCESS
MEMORY TYPE
FACTORY DEFAULT
READ ACCESS
WRITE ACCESS
MEMORY TYPE
Fast-comparison DAC threshold adjust for low TXP. This value is subtracted from the APC DAC value recalled
from Table 06h. If the difference is less than 0x00, 0x00 is used. Comparisons less than V
against V
Fast-comparison DAC threshold adjust for high LOS. The combination of HLOS and LLOS creates a hysteresis
comparator. As RSSI falls below the LLOS threshold, the LOS LO alarm bit is set to 1. The LOS alarm remains set
until the RSSI input is found above the HLOS threshold setting, which clears the LOS LO alarm bit and sets the
LOS HI alarm bit. At power-on, both LOS LO and LOS HI alarm bits are 0 and the hysteresis comparator uses the
LLOS threshold setting.
Fast-comparison DAC threshold adjust for low LOS. See HLOS (Table 02h, Register BEh) for functional description.
BIT 7
BIT 7
BIT 7
______________________________________________________________________________________
2
2
2
7
7
7
MON2
, create a TXP LO alarm. The same ranging applied to the APC DAC should be used here.
2
2
2
6
6
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
2
5
5
5
V
LTXP
V
V
=
HLOS
LLOS
Full Scale
2
2
2
255
4
4
4
=
=
Full Scale
Full Scale
255
255
(
APC DAC LTXP
2
2
2
3
3
3
HLOS
LLOS
)
2
2
2
2
2
2
2
2
2
1
1
1
LTXP
, compared
BIT 0
BIT 0
BIT 0
2
2
2
0
0
0
69