DS1878T+T&R Maxim Integrated Products, DS1878T+T&R Datasheet - Page 12

• Manufacturer Part Number: DS1878T+T&R
• Description: IC CTLR SFP W/DGTL LDD RX 28TQFN
• Manufacturer: Maxim Integrated Products
• Type: SFP+ Controllerr

Specifications of DS1878T+T&R

• Input Type: *
• Output Type: *
• Interface: *
• Current - Supply: *
• Mounting Type: Surface Mount
• Package / Case: 28-WFQFN exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

The DS1878 integrates the control and monitoring func-
tionality required to implement a VCSEL-based or DFB-
based SFP or SFP+ system using Maxim’s limiting
amplifiers and laser drivers. Key components of the
device are shown in the Block Diagram and described
in subsequent sections.
SFP+ Controller with Digital LDD Interface
12
______________________________________________________________________________________
680Ω
+3.3V
Detailed Description
R
BD
PIN-ROSA
DFB TOSA
R
MON
BMON
MON1
MON2
MON3
CS2
CS1
3W
3W
3W
LA
LDD
MAX3945
MAX3946
DS1878
EEPROM
The device controls two 9-bit DACs inside the Maxim
laser drivers. One DAC is used for laser bias control,
while the other is used for modulation amplitude control.
The device communicates with the laser driver over a 3-
wire digital interface (see the 3-Wire Master for
Controlling the Maxim Laser Driver section). The com-
munication between the device and Maxim laser driver
and/or limiting amplifier is transparent to the end user.
QUICK
MODE
TRIP
ADC
LOS
BIAS
DAC
DAC
RSELOUT
I
DISABLE
2
TXDOUT
LOSOUT
TXFOUT
C
FAULT
RSEL
LOS
TXD
SDA
SCL
LOS
TXF
Typical Operating Circuit
TX_FAULT
TX_DISABLE
MODE_DEF2 (SDA)
MODE_DEF1 (SCL)
RATE SELECT
LOS
3-Wire DAC Control