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HA0378T Rev C Feb 2019
Chapter 3
3.9 Controller Schematic Diagram
The PPC001 controller and LPS710 piezo stage bundle is a closed-loop position
control system with a digital PID controller and dual notch filters. The stage contains
a capacitive position sensor for accurate position measurement. The sensor is driven
from a sine wave generator, the AC output signal of the actuator is demodulated and
sampled by a precision 18 bit A/D converter. The output from the capacitive sensor is
linearized in the digital domain and for maximum accuracy the linearizing curve is
individually matched to the sensor. The setpoint position is maintained by a PID
controller whose coefficients can be tuned to optimize system response. The PID
controller is followed by a dual notch filter that, when enabled, dampens the natural
mechanical resonance exhibitied by the mass and elasticity of the stage.
Fig. 3.7 System Schematic - Part 1
LPS710
Synchronous
Demodulator
EXT IN BNC
EXT OUT BNC
18 bit ADC
24 bit ADC
20 bit DAC
24 bit ADC
18 bit DAC
Low-pass
Filter
Divide by 15
Sine Wave
Generator
To Linearization
See Fig 3.8
From Open/Closed Loop
see Fig. 3.8
High voltage amplifier
-25 to +150 V
