GW Instek SFG-1000 Series - Manual (Page 31)

Application Examples
31
Test step
1. Apply a triangle waveform to the amplifier first.
Adjust the waveform amplitude to make sure there
is no clipping.
2. Switch to square waveform and adjust its frequency
to the middle of the amplifier pass band, such as
20Hz, 1kHz, and 10kHz.
3. Observe the shape of the amplifier output. The
following table shows the possible output
distortions and their explanations.
•
Amplitude reduction at low
frequency
•
No phase shift
Transient
characteristiclist
•
Low frequency boosted (accentuated
fundamental)
•
High frequency loss
•
No phase shift
•
Low frequency phase shift
•
Trace thickened by hum-voltage
•
High frequency loss
•
Phase shift
•
Low frequency loss
•
Phase shift
•
Low frequency loss
•
Low frequency phase shift
•
High frequency loss
•
Low frequency phase shift
•
Damped oscillation
Note
For narrow band amplifier testing, square wave may not
be suitable.