Santa Clara, Calif.National Semiconductor Corp. has introduced four current-mode logic (CML) signal-conditioning buffers and multiplexers with 25-picoseconds of jitter, which the company claims is the best signal integrity in the industry.
The DS25BR400 and DS42BR400, configured as quad transceivers or eight-channel buffers, provide a high level of integration for high-speed data-transmission applications. The DS25BR200 operates up to 2.5 Gbits/s and the DS42BR400 operates up to 4.25 Gbits/s. The DS25MB200 and DS42MB200 are dual, signal-conditioning 2:1 multiplexers and 1:2 fan-out buffers (dual channel mux-buffers) designed for use in redundancy data paths. The devices are aimed at enhancing the data-transmission performance of ASICs and FPGAs.
"These devices are manufactured on National's new proprietary BiCMOS8 Silicon Germanium process," said Stephen Kempainen, Interface Marketing Director at National. "That along with the creative circuit design technique enables this low jitter specification."
The family features integrated equalizers and programmable pre-emphasis for low-jitter and flawless transmission of multi-gigabit traffic over low-cost PCB materials, copper cabling and fiber optics. Multi-gigabit applications often require signal-integrity features, such as equalization and boost, for reliable data transfer between the source and destination.
"Previous families of parts did not have both EQ and pre-emphasis; they had one or the other. This new enhancement provides for the best overall signal integrity," Kempainen said.
National's buffer and multiplexer family can provide error-free transmission across more than 80 inches of FR-4 backplanes. Backplane applications include XAUI and fiber channel, as well as the emerging standards for third-generation cellular base stations such as the common public radio interface (CPRI) and open base station standard architecture initiative (OBSAI). The buffer and multiplexers also work at up to 15 meters of PCI Express, SATA, CAT6/CAT7, DVI, HDMI and InfiniBand cables.
"The flow through pin-out design enables easy placement and routing on the PCB for high-speed signals," Kempainen said.
An input equalizer that removes inter-symbol interference (ISI) jitter precedes each input buffer, compensating for up to 5-dB of transmission loss, which results in reducing output jitter to as low as 25-picoseconds. The outputs feature adjustable de-emphasis to reduce deterministic jitter. The devices also offer typical edge rates as fast as 80-picoseconds, high channel-to-channel noise immunity, low output skew and power at less than 140-mW per channel.
'The buffers and multiplexers add robustness and reliability to the data-transfer solution. Now the designer can guarantee a better bit-error rate for the design over the lifetime of the system," he said.
DS42BR400 and DS25BR400 quad transceiver buffers
Available in a 60-pin LLP package, the DS42BR400 operates as a quad transceiver or an eight-channel buffer up to 4.25 Gbits/s or down to 250-Mbits/s. The operating range enables use of the buffer in applications requiring both low- and high-frequency data rates. The DS25BR400 has the same features and packaging as the DS42BR400, but features 250-Mbits/s to 2.5-Gbits/s data rate for 4x PCI-Express, CPRI and OBSAI applications.
For more information on the DS42BR400 and DS25BR400, to order samples and an evaluation board, or to download an application note, visit: www.national.com/pf/DS /DS42BR400.html and www.national.com/pf/DS/DS25BR400.html.
DS42MB200 and DS25MB200 dual multiplexers and buffers
Available in a 48-pin LLP package, the DS42MB200 is a dual, signal-conditioning 2:1 multiplexer and 1:2 fan-out buffer designed for use in backplane redundancy applications. The DS42MB200 operates from 0.8 Gbits/s to 4.25 Gbits/s, making it suitable for adding redundancy to XAUI or fiber channel backplanes. The DS25MB200 has the same features and packaging as the DS42MB200, but offers 0.8 Gbits/s to 2.5 Gbits/s for 2x PCI-Express, CPRI and OBSAI backplanes.
For more information on the DS42MB200 and DS25MB200, to order samples and an evaluation board, or to download an application note, visit: www.national.com/pf/DS/DS42MB200T.html and www.national.com/pf/DS/DS25MB200.html.
An on-demand online seminar, "Boosting FPGA and CPLD Interface Performance for Off-board Data Transmission," is available for viewing at www.national.com/AU/design/0,4706,0_61_,00.html
National's four buffer/multiplexers are available now. In 1,000-unit quantities, the DS42BR400 is priced at $19.50, the DS25BR400 is $14.25, the DS42MB200 is $19.25 and the DS25MB200 is $10.50.
National Semiconductor Corp., 1-800-272-9959, www.national.com