DS1874,pdf datasheet (SFP Cont

The DS1874 controls and monitors all functions for SFF,
SFP, and SFP+ modules including all SFF-8472 functionality.
The combination of the DS1874 with the
MAX3798/MAX3799 laser driver/limiting amplifier provides
APC loop, modulation current control, and eye
safety functionality. The DS1874 continuously monitors
for high output current, high bias current, and low and
high transmit power to ensure that laser shutdown for
eye safety requirements are met without adding external
components. Six ADC channels monitor VCC, temperature,
and four external monitor inputs (MON1–MON4)
that can be used to meet all monitoring requirements.
MON3 is differential with support for common mode to
VCC. Two digital-to-analog (DAC) outputs with temperature-
indexed lookup tables (LUTs) are available for additional
monitoring and control functionality.