The TLK2501 is a member of the transceiver family of multigigabit transceivers used in ultrahigh-speed
bidirectional point-to-point data transmission systems. The TLK2501 supports an effective serial interface
speed of 1.5 Gbps to 2.5 Gbps, providing up to 2 Gbps of data bandwidth. The TLK2501 is pin-for-pin compatible
with the TLK2500. The TLK2501 is both pin-for-pin compatible with and functionally identical to the TLK1501,
a 0.6 to 1.5 Gbps transceiver, and the TLK3101, a 2.5 to 3.125 Gbps transceiver, providing a wide range of
performance solutions with no required board layout changes.
The primary application of this chip is to provide very 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.
This device can also be used to replace parallel data transmission architectures by providing a reduction in the
number of traces, connector terminals, and transmit/receive terminals. 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. It 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 TLK2501 performs data conversion parallel-to-serial and serial-to-parallel. The clock extraction functions
as a physical layer interface device. The serial transceiver interface operates at a maximum speed of 2.5 Gbps.
The transmitter latches 16-bit parallel data at a rate based on the supplied reference clock (GTX_CLK). The
16-bit parallel data is internally encoded into 20 bits using an 8-bit/10-bit (8B/10B) encoding format. 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 extracted reference clock (RX_CLK). It then decodes the 20 bit wide data using
8-bit/10-bit decoding format resulting in 16 bits of parallel data at the receive data terminals (RXD0-15). The
outcome is an effective data payload of 1.20 Gbps to 2.0 Gbps (16 bits data x the GTX_CLK frequency).
The TLK2501 is housed in a high performance, thermally enhanced, 64-pin VQFP PowerPAD package. Use
of the PowerPAD package does not require any special considerations except to note that the PowerPAD, which
has an exposed die pad on the bottom of the device, is a metallic thermal and electrical conductor. It is
recommended that the TLK2501 PowerPAD is soldered to the thermal land on the board. All ac performance
specifications in this data sheet are measured with the PowerPAD soldered to the test board.