SNLS144K June 2005 – March 2024 DS40MB200
PRODUCTION DATA
In a typical design, the DS40MB200 equalizes a short backplane trace on its input, followed by a longer trace at the DS40MB200 output. In this application example, a 25-inch FR4 coupled micro-strip board trace is used in place of the short backplane link. A block diagram of this example is shown in Figure 8-3.
The 25-inch microstrip board trace has approximately 6 dB of attenuation between 375 MHz and 1.875 GHz, representing closely the transmission loss of the short backplane transmission line. The 25-inch microstrip is connected between the pattern generator and the differential inputs of the DS40MB200 for AC measurements.
TRACE LENGTH | FINISHED TRACE WIDTH W | SEPARATION BETWEEN TRACES | DIELECTRIC HEIGHT H | DIELECTRIC CONSTANT εR | LOSS TANGENT |
---|---|---|---|---|---|
25 inches | 8.5 mil | 11.5 mil | 6 mil | 3.8 | 0.022 |
The length of the output trace may vary based on system requirements. In this example, a 40-inch FR4 trace with similar trace width, separation, and dielectric characteristics is placed at the DS40MB200 output.
As with any high-speed design, there are many factors which influence the overall performance. Following is a list of critical areas for consideration and study during design.