General Description
The DS1873 controls and monitors all functions for SFF, SFP, and SFP+ modules including all SFF-8472 functionality. The DS1873 provides APC loop, modulation current control, and eye safety functionality. The DS1873 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.

FEATUREs
♦ Meets All SFF-8472 Control and Monitoring Requirements
♦ Six Analog Monitor Channels: Temperature, VCC, MON1–MON4
   MON1–MON4 Support Internal and External Calibration
   Scalable Dynamic Range
   Internal Direct-to-Digital Temperature Sensor
   Alarm and Warning Flags for All Monitored Channels
♦ Four 10-Bit Delta-Sigma Outputs with 36 Entry Temperature LUTs
  Laser Bias Controlled by APC Loop and Temperature LUT to Compensate for Tracking Error
  Laser Modulation Controlled by 72-EntryTemperature LUT
  Two Additional DACs Controlled by One 72-Entry and One 36-Entry Temperature LUT
♦ Digital I/O Pins: Five Inputs, Five Outputs
♦ Comprehensive Fault-Measurement System with Maskable Laser Shutdown Capability
♦ Flexible, Two-Level Password Scheme Provides Three Levels of Security
♦ 120 Bytes of Password-1 Protected Memory
♦ 128 Bytes of Password-2 Protected Memory in Main Device Address
♦ 256 Additional Bytes Located at A0h Slave Address
♦ I2C-Compatible Interface
♦ +2.85V to +3.9V Operating Voltage Range
♦ -40°C to +95°C Operating Temperature Range
♦ 28-Pin TQFN (5mm x 5mm) Package