SE Input and SE Output (TAS5601 Stereo Configuration)

Twisted-PairWire

Generator

EvaluationModule

AudioPower

Amplifier

Twisted-PairWire

Analyzer

TAS5601

The SE input and output configuration is used with class-AB amplifiers. A block diagram of a fully SE

measurement circuit is shown in Figure 20. SE inputs normally have one input pin per channel. In some cases,

two pins are present; one is the signal and the other is ground. SE outputs have one pin driving a load through

an output ac-coupling capacitor and the other end of the load is tied to ground. SE inputs and outputs are

considered to be unbalanced, meaning one end is tied to ground and the other to an amplifier input/output.

The generator should have unbalanced outputs, and the signal should be referenced to the generator ground for

best results. Unbalanced or balanced outputs can be used when floating, but they may create a ground loop that

affects the measurement accuracy. The analyzer should have balanced inputs to cancel out any common-mode

noise in the measurement.

Figure 20. SE Input—SE Output Measurement Circuit

The following general rules should be followed when connecting to APAs with SE inputs and outputs:

• Use an unbalanced source to supply the input signal.

• Use an analyzer with balanced inputs.

• Use twisted-pair wire for all connections.

• Use shielding when the system environment is noisy.

• Ensure the cables from the power supply to the APA, and from the APA to the load, can handle the large

currents (see Table 3).

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