
User Manual
E727T0005, valid for E-727
BRO, 2019-06-28
Physik Instrumente (PI) GmbH & Co. KG, Auf der Roemerstrasse 1, 76228 Karlsruhe, Germany
Page 220 / 240
Phone +49 721 4846-0, Fax +49 721 4846-1019, Email
Overvoltage category
II
Protection class
I
Degree of pollution
2
Degree of protection
according to IEC 60529
IP20
Operating Limits
In order to achieve minimum distortion of the output waveform, it is important to ensure that the
amplitude of higher-frequency control input is reduced in proportion to the fall-off of the output
voltage at these frequencies. For exact information on maximum operating frequency with a given
piezo load (capacitance), refer to the individual operating limit graphs in the figure below.
Note that the operating limits of a given piezo amplifier depends on the amplifier power, the
amplifier design, and, of course the capacitance of the piezo actuator. The capacitance of piezo
ceramics changes significantly with amplitude, temperature, and load-up to approximately 200% of
the unloaded, small-signal capacitance at room temperature.
The following equations describe the relationship between (reactive) drive power, actuator
capacitance, operating frequency and drive voltage.
The average power that a piezo amplifier has to be able to provide for sinusoidal operation is given
by:
Pa ≈ C ∙ U
supply · Up-p · f
Peak power for sinusoidal operation is:
Pmax ≈ π ∙ C ∙ U
supply · Up-p · f
Where:
Pa = average power [W]
Pmax = peak power [W]
C = PZT actuator capacitance [farad (As/v)]
f = operating frequency [Hz]
Usupply = nominal voltage of the amplifier [V];
182 V with E-727
Up-p = peak-peak drive voltage [V]