General Description
The DS1864 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.

FEATUREs
♦ 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 Two User-Selectable Full-Scale Ranges (0.5mA or 1.5mA) Values Changeable Every 2°C
♦ 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)