AM79761

PRELIMINARY Am79761 Physical Layer 10-Bit Transceiver for Gigabit Ethernet (GigaPHY™-SD) DISTINCTIVE CHARACTERISTICS n Gigabit Ethernet Transceiver operates at 1.25 Gigabits per second (Gbps) n Suitable for both Coaxial and Optical Link applications n 10-bit TTL Interface for Transmit and Receive Data n Monolithic Clock Synthesis and Clock Recovery requires no external components n Word Synchronization Function (Comma Detect) n Low Power Operation - 700 mW typical n 64-pin Standard PQFP — 14 x 14 mm (0˚ C - 70˚ C) — 10 x 10 mm (0˚ C - 50˚ C) n 125 MHz TTL Reference Clock n Loopback Diagnostic n Single +3.3 V Supply GENERAL DESCRIPTION The Am79761 Gigabit Ethernet Physical Layer Serializer/Deserializer (GigaPHY-SD) device is a 1.25 Gbps Ethernet Transceiver optimized for Gigabit Ethernet/ 1000BASE-X applications. It implements the Physical Medium Attachment (PMA) layer for a single port. The GigaPHY-SD device can interface to fiber-optic media to support 1000BASE-LX and 1000BASE-SX applications and can interface to copper coax to support 1000BASE-CX applications. The functions performed by the device include serializing the 8B/10B 10-bit data for transmission, deserializing received code groups, recovering the clock from the incoming data stream, and word synchronization. When transmitting, the GigaPHY-SD device receives 10-bit 8B/10B code groups at 125 million code groups per second. It then serializes the parallel data stream, adding a reference clock, and transmits it thro...