TLK1521 Datasheet, PDF (2/19 Pages) Texas Instruments – 500 Mbps to 1.3 Gbps TRANSCEIVER

TLK1521
500 Mbps to 1.3 Gbps TRANSCEIVER
SLLS591A− OCTOBER 2003 − REVISED JANUARY 2004
description
The TLK1521 is a member of the WizardLink family of multi-gigabit transceivers, intended for use in high-speed
bidirectional point-to-point data transmission systems. The TLK1521 supports an effective serial interface
speed of 500 Mbps to 1.3 Gbps, providing up to 1.17 Gbps of data bandwidth.
The primary application of the TLK1521 is to provide high-speed I/O data channels for point-to-point baseband
data transmission over controlled impedance media of approximately 50 Ω. The transmission media can be
printed-circuit board, copper cables, or fiber-optic cable. The maximum rate and distance of data transfer is
dependent upon the attenuation characteristics of the media and the noise coupling to the environment.
The TLK1521 can also be used to replace parallel data transmission architectures by providing a reduction in
the number of traces, connector pins, and transmit/receive pins. Parallel data loaded into the transmitter is
delivered to the receiver over a serial channel, which can be a coaxial copper cable, a controlled impedance
backplane, or an optical link. The data is then reconstructed into its original parallel format. It offers significant
power and cost savings over current solutions, as well as scalability for higher data rate in the future.
The TLK1521 performs the data parallel-to-serial, serial-to-parallel conversion, and clock extraction functions
for a physical layer interface device. The serial transceiver interface operates at a maximum speed of 1.3 Gbps.
The transmitter latches 18-bit parallel data at a rate based on the supplied reference clock (GTX_CLK). The
18-bit parallel data is internally encoded into 20 bits by framing the 18-bit data with a start and a stop bit. The
resulting 20-bit word is then transmitted differentially at 20 times the reference clock (GTX_CLK) rate. The
receiver section performs the serial-to-parallel conversion on the input data, synchronizing the resulting 20-bit
wide parallel data to the recovered clock (RX_CLK). It then extracts the 18 bits of data from the 20-bit wide data
resulting in 18 bits of parallel data at the receive data pins (RXD0−17). This results in an effective data payload
of 450 Mbps to 1.17 Gbps (18 bits data x GTX_CLK frequency).
The TLK1521 is housed in a high performance, thermally enhanced, 64-pin HTQFP PowerPAD package. Use
of the PowerPAD package does not require any special considerations except to note that the PowerPAD, which
is an exposed die pad on the bottom of the device, is a metallic, thermal, and electrical conductor. It is strongly
recommended that the TLK1521 PowerPAD be soldered to the grounded thermal land on the board, since the
PowerPAD also constitutes a major electrical ground connection for the TLK1521. All ac performance
specifications in this data sheet are measured with the PowerPAD soldered to the test board.
The TLK1521 provides an internal loopback capability for self-test purposes. Serial data from the serializer is
passed directly to the deserializer allowing the protocol device a functional self-check of the physical interface.
The TLK1521 is designed to be hot plug capable. An on-chip power-on reset circuit holds the RX_CLK low and
places the parallel side output signal pins, DOUTTXP and DOUTTXN, into a high-impedance state during power
up.
The TLK1521 uses a 2.5-V supply. The I/O section is 3-V compatible. The TLK1521 is characterized for
operation from −40°C to 85°C.
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