DS1878 Datasheet, PDF (1/101 Pages) Maxim Integrated Products – SFP+ Controller with Digital LDD Interface

19-5537; Rev 1; 8/11
SFP+ Controller with Digital LDD Interface
General Description
The DS1878 controls and monitors all functions for SFF,
SFP, and SFP+ modules including all SFF-8472 func-
tionality. 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 compo-
nents. Six ADC channels monitor V_CC, 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
V_CC. Two digital-to-analog (DAC) outputs with tempera-
ture-indexed lookup tables (LUTs) are available for
additional control functionality.
Applications
SFF, SFP, and SFP+ Transceiver Modules
Ordering Information
PART
TEMP RANGE
PIN-PACKAGE
DS1878T+
-40°C to +95°C
28 TQFN-EP*
DS1878T+T&R
-40°C to +95°C
28 TQFN-EP*
+Denotes a lead(Pb)-free/RoHS-compliant package.
T&R = Tape and reel.
*EP = Exposed pad.
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, V_CC,
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
________________________________________________________________ Maxim Integrated Products 1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.