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Texas Instruments SLOU106 User Manual

Page 26

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3-2

General High-Speed Amplifier Design Considerations

Finally, proper termination of all inputs and outputs must be incorporated into
the layout. Unterminated lines, such as coaxial cable, can appear to be a
reactive load to the amplifier. By terminating a transmission line with its
characteristic impedance, the amplifier’s load then appears to be purely
resistive, and reflections are absorbed at each end of the line. Another
advantage of using an output termination resistor is that capacitive loads are
isolated from the amplifier output. This isolation helps minimize the reduction
in the amplifier’s phase-margin and improves the amplifier stability resulting
in reduced peaking and settling times.