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 customerconfigurable two-level password protection.