27 August 2003 Westlake Village, CA Lightwave -- Inphi Corp. has announced eight new very high-performance ICs for broadband test and measurement applications. These integrated devices build on the company's existing 13-, 25-, and 50-GHz high-speed logic (HSL) offerings and perform critical functions such as clock distribution and retiming in a variety of instrumentation systems.
1:4 Fanout
Inphi's 13726CF 1:4 fanout distributes precise clock or data signals in performance-driven applications. By packaging this functionality onto a single chip, Inphi enables test equipment manufacturers to conserve board space and reduce power levels, resulting in lower system costs, say company representatives. The 13726CF supports clock frequencies up to 15 GHz and data rates up to 20 Gbits/sec and is ideally suited for both high-speed digital logic applications and serial data transmission systems.
"We recently selected Inphi's 1:4 clock fanout for use in our new 13.5-Gbit/sec ParBERT (parallel bit error rate tester)," reports Ingmar Bretz, product manager at Agilent Technologies in Böblingen, Germany. "With very low skew between channels, this part not only met our performance requirements but also enabled us to reduce the number of discrete components in our clock distribution chain and thereby lower our build costs."
2:1 Selector (as multiplexer, switch, and NRZ-to-RZ converter)
Inphi's 20708SE and 20709SE 20-Gbit/sec 2:1 selectors can function as 2:1 multiplexers, 2:1 switches, or NRZ-to-RZ converters. In test and measurement applications and automated test equipment, either of these circuits can be used as a 2:1 multiplexer to serialize two input data streams of up to 10 Gbits/sec into a single 20-Gbit/sec output data stream. The 20708SE or 20709SE can also be used as a 2:1 switch to select between two input data streams of up to 10 Gbits/sec.
In optical transport systems, the 20708SE or 20709SE can operate as an RZ data generator in which an NRZ input data stream of up to 10 Gbits/sec is converted to an RZ output data stream. As NRZ-to-RZ converters, these devices can be used to shape the RZ pulse from 20% to 80% in order to compensate for the deleterious effects of polarization mode dispersion (PMD) in the fiber. The 20708SE and 20709SE exhibit exceptionally low jitter (3 ps peak-to-peak) with fast rise and fall times (less than 25 ps).
Clock Doubler
Optimized to minimize duty cycle distortion and fundamental frequency feedthrough, Inphi's 50714CD and 50715CD clock doublers are designed for applications in which a 35- to 50-GHz clock is required from a 17.5- to 25-GHz input. These parts perform the frequency doubling function in microwave instrumentation and test equipment, for example.
Double Edge-Triggered D Flip-Flop
With its 50704DT and 50705DT double edge-triggered D flip-flops, Inphi has combined the functionality of a D flip-flop and a clock doubler in a single circuit. These devices first double the frequency of an incoming 17.5- to 20-GHz clock and then use the doubled clock to retime the data. This architecture effectively suppresses duty cycle distortion (DCD) to yield output data waveforms with very low jitter, says the company. The 50704DT and 50705DT are well suited for retiming the output of half-rate multiplexers, which often exhibit significant DCD.
Divide-by-8, Modulo-8 Counter
Inphi's divide-by-8 circuits generate a multi-phase clock signal in high-speed digital systems. The 13728DV, 25728DV, and 50728DV and the corresponding positive supply parts support clock frequencies up to 13-, 25-, and 50-GHz, respectively. Each device outputs differential divide-by-8 signals, thus eliminating the need to cascade two discrete circuits (a divide-by-4 and a divide-by-2). These circuits can also be used as modulo-8 counters, which simplifies module design by keeping the pin count low (one input port and one output port).