DS1878

SFP+ Controller with Digital LDD Interface

Meets All SFF-8472 Control and Monitoring Requirements


Please check latest availability status for a specific part variant.

Description

The DS1878 controls and monitors all functions for SFF, SFP, and SFP+ modules including all SFF-8472 functionality. The combination of the DS1878 with Maxim laser driver/limiting amplifier solutions supports VCSEL, DFB, and EML-based solutions. The device provides APC loop, modulation current control, and eye safety functionality. It 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 control functionality.
DS1878: Typical Operating Circuit DS1878: Typical Operating Circuit Enlarge+

Key Features

  • Meets All SFF-8472 Control and Monitoring Requirements
  • Laser Bias Controlled by APC Loop and Temperature LUT to Compensate for Tracking Error
  • Laser Modulation Controlled by Temperature LUT
  • 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
  • Two 9-Bit Delta-Sigma Outputs with 36 Entry Temperature LUTs
  • Digital I/O Pins: Five Inputs, Four Outputs
  • Comprehensive Fault-Measurement System with Maskable Laser Shutdown Capability
  • Flexible, Two-Level Password Scheme Provides Three Levels of Security
  • 256 Additional Bytes Located at A0h Slave Address
  • I²C-Compatible Interface
  • 3-Wire Master to Communicate with a Maxim Laser Driver/Limiting Amplifier
  • +2.85V to +5.5V Operating Voltage Range
  • -40°C to +95°C Operating Temperature Range
  • 28-Pin TQFN (5mm x 5mm x 0.75mm) Package

Applications/Uses

  • SFF, SFP, and SFP+ Transceiver Modules

See parametric specs for Fiber Monitoring and Control (14)


Part NumberADCsResolution
(bits)
# DACs/ ResistorsFS Out
(kΩ)
StepsTemp. SensorMemoryVSUPPLY
(V)
Control InterfacePackage/PinsBudgetary
Price
(See Notes)
DS1878 5-Input Muxable132 DACsNoneNoneInternalEEPROM2.85 to 3.9I2C
TQFN/28
$1.83 @1k

Pricing Notes:
This pricing is BUDGETARY, for comparing similar parts. Prices are in U.S. dollars and subject to change. Quantity pricing may vary substantially and international prices may differ due to local duties, taxes, fees, and exchange rates. For volume-specific and version-specific prices and delivery, please see the price and availability page or contact an authorized distributor.
Product Reliability Reports: DS1878.pdf 
Device   Fab Process   Technology   Sample size   Rejects   FIT at 25°C   FIT at 55°C   Material Composition  

Note : The failure rates are summarized by technology and mapped to the associated material part numbers. The failure rates are highly dependent on the number of units tested.

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