MaxLinear, Inc. Application Specific Clock/Timing XRT91L31IQ

The XRT91L31IQ is a fully integrated SONET/SDH transceiver designed for high-speed applications, supporting both STS-12/STM-4 at 622.08 Mbps and STS-3/STM-1 at 155.52 Mbps. It features an on-chip Clock Multiplier Unit (CMU) that utilizes a high-frequency Phase-Locked Loop (PLL) to generate a high-speed transmit serial clock from a slower external clock reference. The device includes Clock and Data Recovery (CDR) functionality, which can be bypassed for external clock recovery, and supports loop timing applications. This transceiver provides an 8-bit wide LVTTL system interface for serial-to-parallel and parallel-to-serial data conversion, operating at 77.76 Mbps in STS-12/STM-4 mode and 19.44 Mbps in STS-3/STM-1 mode. It can detect and recover SONET/SDH frame boundaries and includes diagnostics features such as Loss of Signal (LOS) monitoring, which automatically mutes received data upon detection. The XRT91L31IQ operates at a supply voltage of 3.3V with a typical power dissipation of less than 660mW in STS-3/STM-1 mode and 800mW in STS-12/STM-4 mode. It is packaged in a 64-pin QFP and is suitable for various applications, including SONET/SDH-based transmission systems, add/drop multiplexers, and multi-service switches.