The TLK1221 gigabit Ethernet transceiver provides for high-speed full-duplex point-to-point data transmissions. These devices are based on the timing requirements of the 10-bit interface specification by the IEEE 802.3 Gigabit Ethernet specification. The TLK1221 supports data rates from 0.6 Gbps through 1.3 Gbps. The primary application of these devices is to provide building blocks for point-to-point baseband data transmission over controlled-impedance media of 50 . The transmission media can be printed-circuit board traces, copper cables or fiber-optical media. The ultimate rate and distance of data transfer is dependent upon the attenuation characteristics of the media and the noise coupling to the environment. The TLK1221 performs the data serialization, deserialization, and clock extraction functions for a physical layer interface device. The transceiver operates at 1.25 Gbps (typical), providing up to 1 Gbps of data bandwidth over a copper or optical media interface. This device supports the defined 10-bit interface (TBI). In the TBI mode, the serializer/deserializer (SERDES) accepts 10-bit wide 8b/10b parallel encoded data bytes. The parallel data bytes are serialized and transmitted differentially at PECL-compatible voltage levels. The SERDES extracts clock information from the input serial stream and deserializes the data, outputting a parallel 10-bit data byte. A comprehensive series of built-in tests is provided for self-test purposes, including loopback and pseudorandom binary sequence (PRBS) generation and verification. Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. PowerPAD is a trademark of Texas Instruments. All other trademarks are the property of their respective owners. PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of the Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters.