Features: . 155Mbps to 3.2Gbps Laser Diode Driver for VCSELs*
. 60ps Rise and Fall Times, 10ps Deterministic Jitter
. Eye Diagram is Stable and Consistent Across
Modulation Range and Temperature
. 1mA to 12mA Modulation Current
. Easy Board Layout, Laser can be Remotely Located
if Desired
. No Input Matching or AC Coupling Components
Needed
. On-Chip ADC for Monitoring Critical Parameters
. Digital Setup and Control with I2CTM Serial Interface
. Emulation and Set-Up Software Available**
. Operates Standalone or with a Microprocessor
. On-Chip DACs Eliminate External Potentiometers
. Constant Current or Automatic Power Control
. First and Second Order Temperature Compensation
. On-Chip Temperature Sensor
. Extensive Eye Safety Features
. Single 3.3V Supply
. 4mm × 4mm QFN PackageApplicationGigabit Ethernet and Fibre Channel Transceivers
SFF and SFP Transceiver Modules
Proprietary Fiber Optic LinksPinout
SpecificationsVDD, VDD(HS).............................................................. 4V
IN+, IN (Cml_en = 1) (Note 6)
Peak Voltage..............VDD(HS) 1.2V to VDD(HS) + 0.3V
Average Voltage.........VDD(HS) 0.6V to VDD(HS) + 0.3V
IN+, IN (Cml_en = 0) (Note 4).0.3V to VDD(HS) + 0.3V
Cml_en = 0 (Note 4)
Peak Difference Between IN+ and IN.................. ±2.5V
Average Difference Between IN+ and IN........... ±1.25V
MODA, MODB (Transmitter Disabled).........0.3V to 2.75V
MODA, MODB
(Transmitter Enabled)............. VDD(HS) 2.75V to 2.75V
EN, SDA, SCL, FAULT.........................0.3V to VDD + 0.3V
MD, SRC...................................................... 0.3V to VDD
Ambient Operating Temperature Range....40°C to 85°C
Storage Temperature Range.................. 65°C to 125°C
DescriptionThe LTC®5100 is a 3.2Gbps VCSEL driver offering anunprecedented level of integration and high speed perfor-mance. The part incorporates a full range of features toensure consistently outstanding eye diagrams. The datainputs are AC coupled, eliminating the need for externalcapacitors. The LTC5100 has a precisely controlled 50Ωoutput that is DC coupled to the laser, allowing arbitraryplacement of the IC. No coupling capacitors, ferrite beadsor external transistors are needed, simplifying layout,reducing board area and the risk of signal corruption. Theunique output stage of the LTC5100 confines the modula-tion current to the ground system, isolating the high speedsignal from the power supply to minimize RFI.
The LTC5100 supports fully automated production with itsextensive monitoring and control features. Integrated 10-bitDACs 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. Statusinformation 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.
LTC5100 Data Sheet
