GS9068 SD SDI Cable Driver

Data Sheet

22213 - 4

August 2010

7 of 11

3.3 Output Return Loss Measurement

To perform a practical return loss measurement, it is necessary to force the GS9068

output to a DC high or low condition. The actual return loss will be based on the outputs

loss will not represent the actual operating return loss.

A simple method of calculating the values of actual operating return loss is to interpolate

the two return loss measurements. In this method, the values of return loss are estimated

The two values of return loss (high and low) will typically differ by several decibels. If

be interpolated as follows:

3.4 Output Amplitude Adjustment

resistor as shown in Figure 3-2 and Table 3-1 below. For an 800mVp-p output with a

nominal ±7% tolerance, a value of 750Ω is required. A ±1% SMT resistor should be used.

Figure 3-2: Output Amplitude Adjustment

1100

1000

900

800

700

700

800

900

1000

R

600

600

500