5 November 2003 Dallas, TX Lightwave -- Dallas Semiconductor, manufacturer of optical control and monitoring products, recently introduced the DS1859-020, a new 20-kilohm, full-scale resistance option for its popular DS1859 SFP controller/monitor.
Similar to the current DS1859-050 (50-kilohm full-scale resistance option), the DS1859-020 controls laser-driver bias and modulation currents, while also managing system monitoring functions required for SFF-8472-compliant optical transceivers. The new 20-kilohm resistance option provides higher adjustment resolution, which is optimal for calibrating some laser drivers, explain company representatives.
The DS1859's high level of integration reduces component count and layout area and speeds up the design of optical transceivers. Control functionality is comprised of two 256-position, nonvolatile (NV) variable resistors with customer-programmed, temperature-indexed EEPROM lookup tables.
An integrated 12-bit analog-to-digital converter (ADC), temperature sensor, and MSA-compliant register and memory architecture provide SFF-8472 diagnostics monitoring functionality. The device monitors three external analog signals, as well as Vcc and temperature. Programmable alarm and warning trip points for all monitored signals alert the system to out-of-tolerance conditions. Additional features include internal calibration and ADC ranging to increase the dynamic range for received optical power measurement. Communication with the devices is achieved over a 2-wire serial interface.
The DS1859 is available in a 4 x 4 BGA package (0.8-mm pitch) or 16-pin TSSOP. It operates from a 2.7-V to 5.5-V power supply over a -40 ° Celsius to +95 ° Celsius temperature range. An evaluation kit is available.