DS1865

www.DataSheet4U.com Rev 0; 3/07 PON Triplexer Control and Monitoring Circuit General Description The DS1865 controls and monitors all the burst-mode transmitter and video receiver biasing functions for a passive optical network (PON) triplexer. It has an APC loop with tracking-error compensation that provides the reference for the laser driver bias current and a temperature-indexed lookup table (LUT) that controls the modulation current. It continually monitors for high output current, high bias current, and low and high transmit power with its internal fast comparators to ensure that laser shutdown for eye safety requirements are met without adding external components. Six ADC channels monitor VCC, internal temperature, and four external monitor inputs (MON1–MON4) that can be used to meet transmitter and video receive signal monitoring requirements. Two digital-to-analog converter (DAC) outputs are available for biasing the video receiver channel, and five digital I/O pins are present to allow additional monitoring and configuration. Features o Meets GEPON, BPON, and GPON Timing Requirements for Burst-Mode Transmitters o Bias Current Control Provided by APC Loop with Tracking-Error Compensation o Modulation Current is Controlled by a Temperature-Indexed Lookup Table o Laser Power Leveling from -6dB to +0dB o Two 8-Bit Analog Outputs, One is Controlled by MON4 Voltage for Video Amplifier Gain Control o Internal Direct-to-Digital Temperature Sensor o Six Analog Monitor Chann...