The DS1864T+ is an SFF-8472 multisource agreement (MSA)-compliant laser controller/monitor that is ideal for SFP optical-transceiver module designs. It controls laser driver bias and modulation currents through a pair of temperature-controlled current-sink DACs. System diagnostics are provided by monitoring three analog inputs, VCC, and temperature through the internal temperature sensor. The device also contains all EEPROM required by the SFF-8472 MSA, including all A0h and A2h EEPROM. The DS1864's memory map can be configured to be compatible with both the DS1852/DS1856 and the DS1859 memory maps. Additionally, memory is secured with customer-configurable two-level password protection. Eye-safety features are integrated by three fast-trip comparators that monitor transmit-power high, transmit-power low, and bias current. The fast-trip comparators drive a FET driver output to disable the laser in the case of eye safety violation. With its integrated laser driver control, system diagnostics, eye-safety features, and internal temperature sensor, the DS1864T+ provides an ideal solution for SFP optical transceiver modules by improving system performance, reducing board space, and simplifying design.
Feature
SFF-8472 MSA Compatible
Five Monitored Channels (Temperature, VCC, MON1, MON2, MON3)
Three External Analog Inputs (MON1, MON2, MON3) Support Internal and External Calibration
Enhanced RSSI Monitoring (26dB Range, 0.5dB Accuracy)
Scalable Dynamic Range for External Analog Inputs
Internal Direct-to-Digital Temperature Sensor Alarm and Warning Flags for All Monitored Channels
Two Linear 8-Bit Current-Sink DACs
Three Fast-Trip Comparators (Tx Power High, Tx Power Low, and Bias Current) for Eye Safety
Flexible, Two Level Password Scheme Provides Three Levels of Security
Provides All Optional and Required SFF-8472 MSA EEPROM (Both A0h and A2h Memory)
I2C-Compatible Serial Interface
Operates from a 3.3V or 5V Supply
-40°C to +95°C Operating Temperature Range
28-Pin TQFN Package (5mm x 5mm)
Applications