LTC5100 Datasheet, PDF (1/52 Pages) Linear Technology – 3.3V, 3.2Gbps VCSEL Driver

LTC5100
3.3V, 3.2Gbps VCSEL Driver
FEATURES
DESCRIPTIO
s _{155Mbps to 3.2Gbps Laser Diode Driver for VCSELs*}
s _{60ps Rise and Fall Times, 10ps Deterministic Jitter}
s _{Eye Diagram is Stable and Consistent Across}
Modulation Range and Temperature
s _{1mA to 12mA Modulation Current}
s _{Easy Board Layout, Laser can be Remotely Located}
if Desired
s _{No Input Matching or AC Coupling Components}
Needed
s _{On-Chip ADC for Monitoring Critical Parameters}
s _{Digital Setup and Control with I}²_C^TM _{Serial Interface}
s _{Emulation and Set-Up Software Available**}
s _{Operates Standalone or with a Microprocessor}
s _{On-Chip DACs Eliminate External Potentiometers}
s _{Constant Current or Automatic Power Control}
s _{First and Second Order Temperature Compensation}
s _{On-Chip Temperature Sensor}
s _{Extensive Eye Safety Features}
s _{Single 3.3V Supply}
s _{4mm × 4mm QFNUPackage}
APPLICATIO S
s _{Gigabit Ethernet and Fibre Channel Transceivers}
s _{SFF and SFP Transceiver Modules}
s _{Proprietary Fiber Optic Links}
The LTC^®5100 is a 3.2Gbps VCSEL driver offering an
unprecedented level of integration and high speed perfor-
mance. The part incorporates a full range of features to
ensure consistently outstanding eye diagrams. The data
inputs are AC coupled, eliminating the need for external
capacitors. The LTC5100 has a precisely controlled 50Ω
output that is DC coupled to the laser, allowing arbitrary
placement of the IC. No coupling capacitors, ferrite beads
or external transistors are needed, simplifying layout,
reducing board area and the risk of signal corruption. The
unique output stage of the LTC5100 confines the modula-
tion current to the ground system, isolating the high speed
signal from the power supply to minimize RFI.
The LTC5100 supports fully automated production with its
extensive monitoring and control features. Integrated 10-bit
DACs eliminate the need for external potentiometers. An on-
board 10-bit ADC provides the laser current and voltage,
as well as monitor diode current and temperature. Status
information is available from the I²C serial interface for feed-
back and statistical process control.
An internal digital controller compensates laser tempera-
ture drift and provides extensive laser safety features.
, LTC and LT are registered trademarks of Linear Technology Corporation.
I²C is a trademark of Philips Electronics N.V.
*Vertical Cavity Surface Emitting Laser
**Downloadable from www.linear.com
TYPICAL APPLICATIO
3.3V
24LC00 EEPROM
IN SOT-23 PACKAGE _VDD
SDA
SCL
MD
ADC
DIGITAL
DAC
CONTROLLER
EN
FAULT
DAC
10nF
SRC
50Ω
SERIALIZER
IN⁺
IN^–
V_SS
100Ω
MODA
+
MODB
–
3.2Gbps
MODULATOR
5100 F01
WARNING: POTENTIAL EYE HAZARD.
SEE “EYE SAFETY INFORMATION”
ARBITRARY
DISTANCE
Figure 1. VCSEL Transmitter with Automatic Power Control
3.2Gbps Electrical Eye Diagram
1mA/DIV
50ps/DIV
5100 TA01
sn5100 5100fs
1