Reference manual - NanoAndMore...Reference manual Tuning Fork Sensor Controller 7 2. Knobs and...
Transcript of Reference manual - NanoAndMore...Reference manual Tuning Fork Sensor Controller 7 2. Knobs and...
Reference manual Tuning Fork Sensor Controller
© March 2019
Version 1.2
NanoAndMore GmbH NanoAndMore USA Corp NanoAndMore Japan K.K.
Spilburg Bld. A1 21 Brennan Street, Suite 10 201 KTTS Building,1-1-1 Waseda
Steinbühlstrasse 7 Watsonville, CA 95076 USA Misato-shi, Saitama-ken 341-0018
D-35578 Wetzlar, Germany [email protected] Japan
[email protected] www.nanoandmore.com [email protected]
www.nanoandmore.com www.nanoandmore.jp
Important notes:
Operating conditions
■ Indoor use only ■ Altitudes below 2000m ■ Ambient temperature in the range 5-40°C ■ Maximum relative humidity 80% at up to 31°C, linearly decreasing to 50% at 40°C ■ Maximum deviations in the power supply up to ±10% from the 100-230V~ 50/60Hz ■ Power supply with transient overvoltages category II ■ Ambient atmosphere with rated pollution degree 2
Installation instructions:
■ The device must be connected to a 100-230V~ 50/60Hz power supply with protective grounding.
Operation manual:
■ The device must be positioned in such a way that the connectors at both ends of the power supply cable are easily accessible.
■ The external surface of the device can be cleaned with a dry piece of soft cloth only. Do not use corrosive or easily combustible solvents!
■ Never use the device for other than its intended purpose! NanoAndMore will assume no responsibility for accident or malfunction caused by improper use.
Maintenance:
■ No periodic maintenance by the manufacturer or an appointed repair representative is required.
■ The fuse is F 2.0A 250V
Quick and simple training
This simple training is for new users to become familiar with the Tuning Fork Sensor Controller. In this example, a tuning fork sensor from NanoAndMore is used.
1) Obtain a sine wave
Please follow the steps above in the described order. Normally, a sine wave should appear on the oscilloscope. If not, please follow the main part of this manual.
2) Experience how the oscillation changes by turning the knobs
The next step is to play with the “Phase”, “Gain”, and “Amplitude” knobs and to look how the oscillation changes. The knobs have to be turned one after the other as described below.
■ “Phase”: Amplitude of the sine wave on the oscilloscope visibly changes. There is a minimum amplitude point, which is the resonance of the sensor and the optimum setting.
■ “Gain”: If the gain is increased too much, the oscillation becomes unstable. ■ “Amplitude”: Amplitude of the sine wave visibly changes. Depending on the amplitude setting, the optimum position of the “Gain” knob is different.
3) Gently stimulate the TF sensor
Gently stimulate the TF sensor, e.g., by blowing on the sensor, and watch how the oscillation changes.
Next steps: To use the frequency measurement function and/or to know more about the controller, please read the main part of the manual.
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Table of contents
Important notes .................................................................................................................... 3
Quick and simple training ..................................................................................................... 4
Content of package .............................................................................................................. 5
1. Introduction ....................................................................................................................... 6
2. Knobs and connectors ...................................................................................................... 7
3. Description of Tuning Fork Sensor Controller system ....................................................... 8
4. Practical operations ......................................................................................................... 11
Step 1: Adjusting of parasitic capacitance compensation .................................................... 11
Step 2: Setting up the self-oscillation of a tuning fork sensor .............................................. 15
Step 3: Setting up the frequency measurement function ..................................................... 16
5. NANOSENSORS™ Akiyama-Probe operation ................................................................ 16
6. Technical data .................................................................................................................. 19
Appendix 1: Circuit diagrams - Self oscillation and phase-locked loop block ............................. 20
Appendix 2: Circuit diagrams - Power supply block’ (left) and ‘Tuning Fork Sensor I/O block ...... 21
Appendix 3: Circuit diagrams - Preamplifier board ............................................................... 22
Content of package
■ Tuning Fork Sensor Controller ■ Preamplifier board with sensor holder ■ Controller-to-preamplifier cable ■ Controller-to-power supply cable ■ Printed version of this manual
This product is an electrostatic sensitive device. Please adopt maximum countermeasures to avoid ESD (Electrostatic Discharge).
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1. Introduction
Commercially available “watch crystals”, with a resonance frequency of 32.768 kHz, are of great interest for various sensing applications such as Scanning Force Microscope (SPM), Atomic Force Microscope (AFM), viscosity/vacuum measurements, bio/chemical sensing, e.t.c.
Most of these sensors are based on a simple working principle: A quartz tuning fork is self-oscillating at its resonance frequency. As soon as an external force, an “influence”, or an environmental change is applied on the tuning fork, the self-oscillation frequency changes. By measuring the frequency shift, one can obtain quantitative information of the analyte.
The NanoAndMore Tuning Fork Sensor Controller is an electronic device to (i) control the self-oscillation of a quartz tuning fork based sensor and to (ii) measure its frequency.
The circuit parameters are particularly optimized for AFM applications with the NANOSENSORS™ Akiyama-Probe (see photo above). However, the NanoAndMore Tuning Fork Sensor Controller can be applied for other sensors based on the same type of quartz tuning fork.
The NanoAndMore Tuning Fork Sensor Controller in conjunction with the preamplifier included in the package can self-excite a quartz tuning fork sensor at its resonance frequency. The sensor is driven by an analog signal (normally a sine wave), and the vibration amplitude of the tuning fork is kept at a setpoint by a feedback loop. The phase-locked loop (PLL) of the NanoAndMore Tuning Fork Sensor Controller measures the self-oscillation frequency and yields an analog output.
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2. Knobs and connectorsThe front panel
■ +V, -V : monitor of DC power on the board ■ Sensor : Terminal to be connected to the preamplifier board with the provided cable. ■ Amplification : Set amplification for the signal from the sensor, High (×10) or Low (×2.4) ■ Sensor drive : Select the driving signal to the sensor, either an external signal supplied to the BNC on the side or an internal signal for self-oscillation. (Important: The signal applied on the terminal should be limited between -10 V to +10 V.)
■ Phase : Control the phase shifter in the self-oscillation loop ■ Gain : Control gain of the amplitude controller in the self-oscillation loop ■ Amplitude : Set the signal amplitude to be maintained in the self-oscillation loop ■ Local osc. tune: Set the local oscillator frequency, The selector changes the tunable frequency range: TF (27.4 kHz ~ 37.9 kHz), A-Probe (37.6 kHz ~ 60.4 kHz) (± 1 kHz variations in different units)
■ Δf out : Frequency shift output terminal. The output range is from -10V to +10V. ■ Freq. range : Demodulation frequency range, Wide = ± 2077 Hz (± 150Hz variations in different units), Narrow = ± 405 Hz (± 30Hz variations in different units)
■ Polarity : Pos. (sensor frequency UP-> Δf out UP), Neg. (sensor frequency UP -> Δf out DOWN) ■ Monitor : Select one of the signals at different points in the self-oscillation loop. The output range of the monitor terminal is from -10V to +10V.
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The back panel
On the back panel, there are the power entry socket, the fuse box, and the power switch. The AC power supply should be 100-230V~ 50/60Hz. The fuse is F 2.0A 250V. When the proper DC power is supplied on the internal circuit board, the LEDs on the front panel illuminate.
3. Description of Tuning Fork Sensor Controller system
The following figure shows the overall system of the NanoAndMore Tuning Fork Sensor Controller (TFSC). The electronics in the TFSC box consist of two circuit blocks. One is a self-oscillation block which forms an electrical loop together with the preamp (separated unit) to enable a self-oscillation of a quartz tuning fork (TF) at its resonance frequency with constant amplitude. The other block is a frequency measurement unit including a Phase-Locked Loop (PLL) circuit.
Power switch
Fuse
Power line
Amplification
High: x10Low: x2.4
(Amplification)
Amplitude measurement
Amplitude controller
Gain control(Gain)
Monitor (Amplitude)
Monitor( )
Multiply
Phase shifter
Monitor(PI gain)
Phase control(Phase)
Phase Locked Loop (PLL)
Local oscillator
Frequency turning(Local osc. tune)
ComparisonAnalog output( f out)
Output polarity(Polarity)
Frequency range(TF or A-Probe)
Demodulation frequency range(Freq. range)
Monitor(Comparator)
From preamp
To preamp
Monitor(Drive signalFrom sensor )
Selector(Sensor drive)
Signal from external source
10:1Reduction
Gain control(Trimmer for the parasitic capacitance compensation)
From controller
To controller
-GI-V x1
Cantilever is at virtual ground potential. (Akiyama-Probe)
Frequency measurement
Self-oscillation
Preamp
Set amplitude(Amplitude)
Amplification Amplitude measurement
Amplitude controller
Phase shifter
Phase Locked Loop (PLL)
Local oscillator
Comparison
10:1Reduction -G
I-V x1
-
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Sensor holder
The preamplifier board and the sensor holder are fabricated on a single PCB. The sensor holder is designed for mounting the ceramic plate of the NanoAndMore TF sensor and NANOSENSORS™ Akiyama-Probe. The sensors with the ceramic plates can be easily slipped in the slot and held on the spot. The two spring pins provide the in/out signals to/from the TF. The sensor holder can be separated from the preamplifier board by cutting the PCB and mounted apart, if this is preferable. The three electrical connections, however, should be as short as possible.
--- Preamplifier board and sensor holder ---
In order to perform an accurate measurement with a TF sensor, only the piezoelectric current must be measured. The base current flowing through a parasitic capacitance related to the sensor must be compensated. This is done by adjusting the trimmer on the preamplifier board.
!!! Important note !!!
The preamplifier and sensor holder board are not shielded from external electromagnetic disturbances. They should be used inside of an electromagnetically shielding enclosure.
Preamplifier board
At the first stage of the preamplifier board, the TF driving signal coming from the TFSC is attenuated by a factor of ten. The signal is then supplied to the TF sensor as well as the parasitic capacitance compensation line. The outputs from both lines are summed such that only the piezoelectric-current of the TF is amplified by current-voltage converter. The output is buffered at the final stage on the board and fed to the TFSC.
In case of the Akiyama-Probe, the silicon cantilever and tip are electrically connected to the left pad of the ceramic plate through one of the electrodes of the TF. Upon mounting the Akiyama-Probe on the sensor holder, the left pad is connected to the virtual ground terminal of the current-voltage convertor. Consequently, the cantilever and tip have the virtual ground potential.
Sensor holder
Trimmer for the parasitic capacitance compensation
Preamplifier boardSensor holder
Trimmer for the parasitic capacitance compensation
Preamplifier board
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Self-oscillation block
A signal from the preamp is amplified at the first stage. The amplification can be set either High (×10) or Low (×2.4). The first choice should be Low. If the Q factor of the sensor is very low and a self-oscillation cannot be obtained, one needs to select the high amplification. The amplified signal can be monitored from the monitor terminal, by selecting “From sensor”.
At the second stage, the amplitude of the amplified signal is measured. The measured value can be monitored as “Amplitude”. The amplitude controller at the following stage includes a proportional-integral (PI) regulator and maintains the measured amplitude at a constant value set by the “Amplitude” knob. The gain of the amplitude controller is set by the “Gain” knob. The output from the amplitude controller can be monitored from the monitor terminal, by selecting “PI gain”.
The amplified signal at the first stage and the amplitude controller output are multiplied and fed to a phase shifter. A certain phase shift controlled by the “Phase” knob is applied to the signal. The yielded signal can be monitored as “Drive signal”. Finally, the signal is fed to the preamp through the “Sensor drive” switch.
It is possible to apply an external driving signal to the sensor through the “Sensor drive” terminal.
Frequency measurement block
The frequency measurement block includes a Phase-Locked Loop (PLL) circuit. It measures the self-oscillation frequency and generates an analog signal proportional to a difference between the self-oscillation frequency and an internal reference. The frequency of the internal reference is set by the “Local osc. tune” knob and the range selector.
This frequency measurement block is independent from the self-oscillation loop. It does not influence the self-oscillation of the sensor.
Example (the self-oscillation frequency is 45.000 kHz):
The range selector should be set on the position “A-Probe”. By turning the “Local osc. tune” knob, one can find the point where the analog output at the Δf out terminal is 0V. With these settings, the output will follow the change up to the demodulation frequency range selected by “Freq. range”, if the self-oscillation frequency changes.
Frequency measurement(PLL)
Local oscillator
Frequency turning(PLL tune: to be adjusted)
Comparison
Output polarity(Positive)
Frequency range(37.6 kHz – 60.4 kHz range)
Demodulation frequency range(± 405 Hz range)
E.g., 45.000 kHz
Monitor(Comparator)
+10 V
0 V
-10 V 405 Hz 405 Hz
45.000 kHz
bigger smaller PLL tune
Δf out
45.405 kHz44.595 kHz
Frequency measurement(PLL)
Local oscillator
Frequency turning(PLL tune: to be adjusted)
Comparison
Output polarity(Positive)
Frequency range(37.6 kHz – 60.4 kHz range)
Demodulation frequency range(± 405 Hz range)
E.g., 45.000 kHz
Monitor(Comparator)
+10 V
0 V
-10 V 405 Hz 405 Hz
45.000 kHz
bigger smaller PLL tune
Δf out
45.405 kHz44.595 kHz
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In this example, “Freq. range” is set “Narrow (± 405 Hz)”. A frequency change from 44.595 kHz to 45.405 kHz can be measured and the corresponding output at the Δf out terminal is from -10 V to +10 V. The output polarity can be inversed by “Polarity” selector setting.
4. Practical operations
In this chapter, practical steps to setup/optimize the TFSC for measurements are described. There are three steps which have to be followed: Step 1 -> Step 2 -> Step 3 -> measurements.
Step 1, Set the trimmer on the preamplifier board.
Step 2, Start the self-oscillation and optimize parameters.
Step 3, Set up the frequency measurement function and obtain an analog output.
The initial preparations before the three steps are as follows:
■ Fix the sensor holder and the preamplifier board. ■ Connect the preamplifier board and the TFSC with the provided cable. ■ Connect the AC power cable. The power switch is OFF at this moment. ■ Mount a TF sensor on the sensor holder.
Step 1: Adjusting of parasitic capacitance compensation
There are three options for adjusting the parasitic capacitance compensation by tuning the trimmer on the preamplifier board. Choose one of the options according to the available external instruments. This procedure must be carried out each time after the TF sensor is exchanged.
Option 1:
If a parameter analyzer (Gain-phase, Network, Lock-in amplifier, etc.) is available.
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■ Set “Sensor drive” switch to “Ext.” and “Monitor” selector to “From sensor” ■ Set the selector of “Local osc. tune” depending on the sensor type. ■ Set “Amplification” switch to “Low” (this is the first choice. If Q of the sensor is very small, this switch would need to be “High”.)
■ Connect the reference output channel of the parameter analyzer and “Sensor drive” input with a 50Ω BNC cable.
■ Connect the test channel of the parameter analyzer and “Monitor” output with a 50Ω ■ Turn power switch ON, make sure both +V and –V power LEDs are on. ■ Start a frequency sweep function of the parameter analyzer. The amplitude is set e.g., 1 V peak-peak.
■ Find a resonance peak and make the sweep range narrower, e.g., 1 kHz. ■ Turn the small screw of the trimmer on the amplifier board (see “Preamplifier board and sensor holder” on p. 9) with a screwdriver so that the amplitude curve becomes symmetric around the resonance peak. The middle picture below shows the optimum setting.
Option 2:
If a sine wave generator with frequency sweep function and an oscilloscope are available.
Ampl
itude
(log
)
frequency
Ampl
itude
(log
)
frequency
Ampl
itude
(log
)
frequency
ComparatorComparator
Oscilloscope
Preamplifier board
Selector to “Ext.”
55’000.00
Selector to “Amplitude”
Sine wave generator with frequency sweep mode
First choice “Low”. If Q is very small then “High”.
“Tuning fork sensor”or “A-Probe”
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■ Set “Sensor drive” switch to “Ext.” and “Monitor” selector to “Amplitude” ■ Set the selector of “Local osc. tune” depending on the sensor type. ■ Set “Amplification” switch to “Low” (this is the first choice. If Q of the sensor is very small, this switch would need to be “High”.)
■ Connect the output channel of the sine wave generator and “Sensor drive” input with a 50Ω BNC cable.
■ Connect an input channel of the oscilloscope and “Monitor” output. ■ Turn power switch ON, make sure both +V and –V power LEDs are on. ■ Start a frequency sweep of the sine wave generator: e.g., center frequency = resonance frequency of the sensor, bandwidth = 2 kHz, amplitude = 1 V peak-peak, sweeping time = 5 seconds
■ Set the time axis of oscilloscope, e.g., 500 ms/div, so that one cycle of the frequency sweep can be monitored.
■ Normally, a peak can be found in the signal on the oscilloscope. If yes, make the sweep range narrower, e.g., 1 kHz, if not, slightly change the center frequency.
■ Turn the small screw of the trimmer on the amplifier board (see “Preamplifier board and sensor holder” on p. 9) with a screwdriver so that the amplitude curve becomes symmetric around the resonance peak.
Option 3:
If a sine wave generator with NO frequency sweep function and a multimeter (or an oscilloscope) are available.
ComparatorComparator
DC 1.2345 V
MultimeterPreamplifier board
Selector to “Ext.”
55’000.0055’000.00
Sine wave generator withNO frequency sweep mode
First choice “Low”. If Q is very small then “High”.
Selector to “Amplitude”“Tuning fork sensor”or “A-Probe”
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■ Set “Sensor drive” switch to “Ext.” and “Monitor” selector to “Amplitude”. ■ Set the selector of “Local osc. tune” depending on the sensor type. ■ Set “Amplification” switch to “Low” (this is the first choice. If Q of the sensor is very small, this switch would need to be “High”.).
■ Connect the output channel of the sine wave generator and “Sensor drive” input with a 50Ω BNC cable.
■ Connect a test channel of the multimeter to “Monitor” output. The multimeter should be set in a DC measurement mode.
■ Turn power switch ON, make sure both +V and –V power LEDs are on. ■ Start the sine wave generator. Set the frequency several kHz higher than the expected resonance of the sensor, e.g., ~60 kHz in case of the Akiyama-Probe and ~40 kHz for the TF sensor. The amplitude is e.g., 1 V peak-peak.
■ Turn the small screw of the trimmer on the amplifier board (see “Preamplifier board and sensor holder” on p. 9) with a screwdriver in order to minimize the amplitude (measure on the multimeter). With these settings, the adjustment of the parasitic capacitance compensation is normally sufficient just to obtain self-oscillation of the sensor. Perform the following steps if you require precise adjustment.
■ First, the signal frequency from the generator is set at the expected sensor resonance. Precisely adjust the frequency in order to obtain a maximum amplitude (measure on the multimeter). Take a note of the frequency and the amplitude.
■ Slightly change the setting of the trimmer on the preamplifier board to one direction. ■ Tune the frequency and find maximum amplitude again. Repeat this step if you obtain a smaller amplitude than before. If the amplitude is increased, turn the trimmer the other direction. The optimum setting is where the amplitude is at its minimum (see the figure below). Note that the amplitude change is usually very small.
optimum(symmetric)
frequency
ampl
itude
optimum(symmetric)
frequency
ampl
itude
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Step 2: Setting up the self-oscillation of a tuning fork sensor
The next step after the adjustment of the parasitic capacitance compensation is to setup a stable self-oscillation of the TF sensor.
■ Turn the power switch OFF. ■ Connect an oscilloscope to the “Monitor” output with a 50Ω BNC cable. ■ Set the “Sensor drive” switch to “Int.” and the “Monitor” selector to “Drive signal”. ■ Set the “Amplification” switch to “Low” (this is the first choice. If Q of the sensor is very small, this switch would need to be “High”.)
■ If the tuning knob parameters are not known, set the “Phase” knob to 5(00), the “Gain” knob to 5, and the “Amplitude” knob to 5 for tuning fork sensors and 1(00)/5/5 for A-probes.
■ Turn the power switch ON. Make sure both +V and –V power LEDs are on. ■ Turn the “Phase” knob until a stable sine wave appears on the oscilloscope. Normally, its frequency is around the resonance frequency obtained in Step 1.
■ Fine-tune the “Phase” knob such that the amplitude of the “Drive signal” appearing on the oscilloscope is minimal.
ComparatorComparator
Oscilloscope
Preamplifier board
Selector to “Int.”
Selector to “Drive signal”
Scanning probe system(z-feed back)
First choice “Low”. If Q is very small then “High”.
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■ As the name suggests, the “Amplitude” knob controls the vibration amplitude of the TF sensor. (In case of the Akiyama-Probe, the tip vibration amplitude in a free space is set by this knob.)
■ The ‘Gain’ knob controls the feedback loop gain of the amplitude control circuit. Normally, it should be set as high as possible, but low enough to keep the signal stable. It is recommended to re-tune this knob each time after the amplitude setting was changed.
Step 3: Setting up the frequency measurement function
At this point, the TFSC can be connected to a planned final measurement setup, e.g., SPM/AFM. The terminal “Δf out” provides an analog signal proportional to a difference between the self-oscillation frequency and an internal reference which can be tuned by the “Local osc. tune” knob.
■ Connect the “Δf out” terminal to a planned measurement setup, if necessary. ■ Set the “Monitor” selector to “Comp. out” ■ Turn the “Local osc. tune” knob until the signal at “Δf out” is nearly 0 V and the “Monitor” output shows a triangle (saw) wave. In fact, there are a couple of circumstances where “Δf out” becomes nearly 0V. However, there is only one setpoint which fulfills the above mentioned two conditions simultaneously.
■ Finally, the “Local osc. tune” knob is set at a setpoint at which “Δf out” yields a preferable voltage, or frequency, offset (Please refer the paragraph “Frequency measurement block” above).
!!! Important note !!!
The preamplifier and sensor holder board are not shielded from external electromagnetic disturbances. They should be used inside of an electromagnetically shielding enclosure.
5. NANOSENSORS™ Akiyama-Probe operationThe best operation mode for NANOSENSORS™ Akiyama-Probe is dynamic mode with frequency modulation (FM) detection, which can be perfectly done using the TFSC. To setup an AFM system with the Akiyama-Probe, only two things have to be done: (i) fixation of the probe on to the AFM head and (ii) electrical connection between the frequency output of the TFSC, “Δf out”, and an input terminal for z-feedback loop of the AFM.
For example, some Veeco/Bruker AFMs are equipped with the so called “Break-out box”, which is an I/O interface with many BNC connectors for different signals. “In0” of this box is the terminal to which an external signal should be fed for the z-feedback. The “Δf out” terminal of the TFSC can be directly connected to the “Input” terminal of “In0” with a 50Ω BNC cable. The switch of “In0” should be positioned on “Input”.
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If you don’t know how to introduce an external signal for the z-feedback, please contact your AFM manufacturer.
In case of Nanoscope III from Veeco/Bruker, if an external input signal for the z-feedback is negative, the AFM program recognizes that the tip is not touching the sample. In contrast, if the signal is positive, the tip is considered to be already at the sample surface (This is a setting of the program.).
When the tip-engaging function (start of scanning) is launched, the program checks the input signal. As long as the signal is negative, the tip is mechanically approached towards the sample. When it becomes 0 V, the approach is stopped and xy-scanning as well as the z-feedback are started. The z-piezo is driven with the feedback loop according to the magnitude of the input signal. A higher input voltage is considered to be a larger cantilever deflection.
The dynamic range of the output of the TFSC is ±10V, which corresponds either to ± 405 Hz or to ± 2077 Hz. The maximum frequency shift (denoted as Δf) of an Akiyama-Probe is approximately 30 Hz ~ 400 Hz (Δf varies depending on temperature and humidity). Normally, the ± 405 Hz range (~24 mV/Hz) is selected for tuning fork sensors and Akiyama-Probe operation.
In ambient conditions, an engaging point should be in the “periodic contact phase” (see figure below). Here, we suppose that a probe has Δf = 200 Hz and that an engaging point should be at 20 Hz shifted position. In this case, an initial frequency out of the TFSC (“Δf out” terminal) should be set to -0.48 V (24 mV/Hz × 20 Hz = 0.48 V, negative = lower frequency) by adjusting the “Local osc. tune” knob. With this setting, the AFM program starts xy-scanning at the desired engaging point.
For measurements in ambient conditions, it is better to use a relatively large tip vibration amplitude. However, each probe has different factors between “Driving voltage” and “Tip amplitude”, e.g., dial “2” at “Amplitude” knob yields 300 nm peak-to-peak for one Akiyama-Probe, but 150 nm- 500 nm for another.
Δf = 200 Hz
Periodic contact phase“Quasi” contactphase
Free oscillation
Z-position
Engaging point
0 V-0.48 V
20 Hz
(± 405 Hz range)
+4.32 V
TFSC output
Frequency shift
Initial offset
A half of peak-peak tip amplitude
Freq
uenc
y sh
ift
90% 10%
Δf = 200 Hz
Periodic contact phase“Quasi” contactphase
Free oscillation
Z-position
Engaging point
0 V-0.48 V
20 Hz
(± 405 Hz range)
+4.32 V
TFSC outputTFSC output
Frequency shiftFrequency shift
Initial offset
A half of peak-peak tip amplitude
Freq
uenc
y sh
ift
90% 10%
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Real amplitude can be estimated from a full stroke approach curve. The z-displacement over which the periodic contact phase is lying corresponds to a half of the peak-peak tip amplitude.
Note that the amplitude of the piezoelectric-current of the TF, which is proportional to the mechanical vibration amplitude of the prongs, is maintained at a set value by the TFSC, but this does not mean that the tip vibration amplitude is also kept at a constant value.
It is recommended to optimize the “Gain” whenever the tip amplitude setting is changed. This is especially important if the probe needs to work with a very small tip amplitude (< 150nm).
For more information about the Akiyama-Probe, please read the references provided by NANOSENSORS™ (www.akiyamaprobe.com).
Although, the TFSC can be configured for the amplitude modulation (AM) detection like shown in the figure below, this mode is not recommended for an operation of the Akiyama-Probe. The reason is that due to the high Q of the Akiyama-Probe, the scan speed would have to be very slow and one would have to compromise the spatial resolution.
ComparatorComparator
Preamplifier board
Selector to “Ext.”
55’000.00
Selector to “Amplitude”
Sine wave generator Scanning probe system(z-feed back)
First choice “Low”. If Q is very small then “High”.
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6. Technical data ■ Self-oscillation frequency range 10 kHz ~ 100 kHz ■ Frequency measurement range (a) 27.4 kHz ~ 37.9 kHz*1
■ (@ Δf out = 0V) (b) 37.6 kHz ~ 60.4 kHz*1 ■ Demodulation output range ± 10 V ■ Demodulation frequency range (i) ± 405 Hz *2 (100 mHz resolution)
(ii) ± 2077 Hz *3 (510 mHz resolution)
■ Demodulation bandwidth ~ 400 Hz ■ Output polarity selection Yes ■ Monitor terminal range ± 10 V ■ Required power supply 100-230V~ 50/60Hz 4VA
*1 ± 1 kHz variations in different units *2 ± 30 Hz variations in different units *3 ± 150 Hz variations in different units
Specifications are subject to change without notice.
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Appendix 1: Circuit Diagrams - Self oscillation and phase-locked loop block
2 37
6
51
8 4
U3
LM31
1
Vin
1
NC
2
-VS
3
Cav
4
dB5
BUF
out
6
BUF
in7
Iout
8Ri
9CO
M10
NC
11N
C12
NC
13+V
S14
U1
AD
536A
JD
C3 100n
F
0VC1
2
1nF
0V
VDD
C11
100n
F
0V
VSS
C13
100n
FR1
71K
P2 K21
P3 K22
R10
100K
-2
+3
1
8 4
U8A
AD
712J
VDD
VSS
C4 220n
F
C14
100n
F
0V
R18
6.8K
VDD
X11
X22
Y13
Y24
-VS
5Z
6
W7
+VS
8
U9
AD
633J
0VVS
S
C17
100n
F
VDD
C6 100n
F
C5 100n
F0V
C7 3300
pF
R210
K-
2
+3
6
7 4
U5
LT13
57
VSS
VDD
C18
100n
F
C9 100n
F
0V0V
R3 33K
C8 10pF
R16
47C1
91n
F
0V
P4 K11
0V0V
VSS
VDD
C20
100n
F0V
R5 10K
C35
100n
F
C21
100n
FD
3ZP
D5.
1
0V
SIG
/IN
2
DET
/IN
16
C213
C114
R12
COM
P/C
AP
6
OP+
9
OP-
7O
P/O
UT
8
VCO
/0-Q
15VC
O/0
-C3
VCO
/0-V
5VR
EF11
DET
/OU
T10
1
4
U2
XR22
12
0V
VDD
C23
100n
F0V
C22
1nF
0VC3
610
0nF
0V
123
JP3
K12
123
JP2
K5
R23
487K
R11
91K
C24
680p
F
0V
R710
K
R26
20K
R27
4.3K
-2
+3
18 4
U7A
LT13
58CN
-6
+5
7
U7B
LT13
58CN
VDD
VSS
R24
22K
C25
10nF
0V
R610
K
R810
K
C37
100n
F0V
C26 10
0nF
0V
R12
100K
C27
220p
F
C38
220p
FR1
310
0K
0V
Ref
1
Vin-
2
Vin+
3
Vss
4Se
nse
5
Vdd
7
V06
NC
8U
10SS
M21
41
VSS
C39
100n
F
0V
0V
C28
100n
F
VDD R2
5
2K
C41
2200
pF
C40
1nF
P23
K1
P27
K10
-6
+5
7 U8B
AD
712J
P13
K18
P10
K13
P11
K14
P12
K15
P20
K16
P21
K17
P14
K19
P22
K20
0V
C16
100n
F0V
C15
100n
F0V
C34
100n
F
C33
100n
F
12
34
56
K1
K4
0V
R15
10K
2 31
1
U12
A
OP4
67
567
2
U12
B
OP4
67
8109
34 11
U12
CO
P467
141213
4
U12
DO
P467
VDD
VSS
0V 0V
R29
47 C48
1nF
0V
R32
47C5
11n
F
0VR3
1
47C5
01n
F
0V
R30
47
C49
1nF
0V
R33
47C5
21n
F
0V
0V
0V
S5 BNC
red
gray
dF O
UT
S4 BNC
MO
NIT
OR
OU
Tre
d
blac
k/vi
olet
SW2
Rota
ry 5
Pos
red
From
sen
sor
blue
PLL
out
(Com
p.)
gree
n
PI g
ain
yello
w
Driv
e si
gnal
whi
te
Am
plitu
degr
ay
0V
P9 K9
P8 K8
R20
10K
10 t
urns
PHA
SEyello
w
green
1tur
n Ce
rmet
whi
tew
hite
GA
IN
R22
1MP5 K
23
P6 K27
0V
P7 K30
R192
10K
AM
PLI
TUD
E
1tur
n Ce
rmet
whi
te gray
blac
k/vi
olet
P26
K29
P25
K28
0V
R21
10K
10 turns
PLL
TUN
E yello
w
gree
n
violet
yello
ww
hite
gree
ngr
ay
oran
ge
blue
brow
n
1 2 3
Freq
. ra
nge
SW5
SW 2
Pos
Wid
e
Nar
row
1 2 3
Loc.
Osc
. tu
ne
SW6
SW 2
Pos
TF A-P
robe
gree
n
0V
1 2 3
4 5 6
Pola
rity
SW7
SW 2
Pos
, 2C
Pos.
Neg
.
red
violet
red
3
2
1
R34
50K
3
2
1
R35
10K
3
2
1
R37
5K
3
2
1
R38
5K
R36
4.3K
R39
47R
3x12
0mm
3x80
mm
2x50
mm
40m
m
60m
m
60m
m
30m
m
30m
m
60m
m
60m
m
6x13
0mm
2x70
mm
60m
m60
mm
2x13
0mm
Loop
Out
Loop
In
oran
ge
35m
m
Reference manual:Tuning Fork Sensor Controller
21
Appendix 2: Circuit Diagrams - Power supply block (A) and Tuning Fork Sensor I/O block (B)
-2
+3
6
7 4
U4
LT13
57
P1 K3
C1 100n
F
R1 10K
0V
C2 100n
F
C10
100n
F
VDD
0V 0VVS
S
1 2 3
JP1
K6
R14
24K
R910
0K
P17
K26
P16
K25
P15
K24
0V
VDD
VSS
123
4 5
S2
BIN
DER
5 p
in
plac
ed o
n th
e fr
ont
pane
l
Back
(so
lder
) vie
w,
S1 BNC
SEN
SOR
I/O
SEN
SOR
DRI
VE
ext.
int.
brown
blac
k/vi
olet
oran
ge
1 2 3
Sens
or d
rive
SW1
SW 2
Pos
1 2 3
Am
pli�
catio
n
SW3
SW 2
Pos
HIG
H
LOW
red
blue
gree
n
0V
gree
n
red
blue
yellow
white
to G
ND
, ne
ar t
o K9
(R20
)
3x55
mm
35m
m
60m
m
70m
m
80m
m
3x60
mm
35m
m
Loop
Out
Loop
In
D1
1N58
17
D2
1N58
17
Vin
1
GND 2
Vout
3U
6LM
7812
C32
100n
F
C31
100n
FC2
910
0nF
C30
100n
F
0V
VDD
VSS
R4 4.7K
P19
K7
P18
K2
0V
P24
K0
P28
KL2
P29
KL3
Vin
2
GND1
Vout
3
U11
LM79
12
C42
100u
F/35
C44
100u
F/25
C43
100u
F/35
C45
100u
F/25
R28
4.7K
P31
K31
P30
K30
0V
LED
2
GRE
EN 5
mm
blac
k/vi
olet
gree
n
LED
1
GRE
EN 5
mm
blac
k/vi
olet
red
+15V
DC
red
-15V
DC
blue
GN
D b
lack
/vio
let
1 2 3 4
X2 Hea
der
4
1 2 3
X1 Hea
der
3AC(
L)
AC(
N)
+15V
-15V0V 0V
PSU
1PD
-251
5
PE
1 3 2
SW
F1 2A
PE
blac
k
blac
k
blac
k
yello
w-g
reen
yello
w-g
reen
X3 BZH
01/Z
0000
/01
INL
ET,
IEC,
SW
ITCH
ED,
built
-in f
use
hold
er
MEA
NW
ELL
100-
240V
AC
2x11
0mm
2x11
0mm
6.5m
m
95m
m
85m
m
10m
m
3x70
mm
1nF/
1kV
C46
1nF/
1kV
C47
0VPE
DN
M C
46,
C47
GN
D (
0V)
is n
ot c
onne
cted
dire
ctly to
the
Chas
sy (PE
)
AB
Reference manual:Tuning Fork Sensor Controller
22
Appendix 3: Circuit Diagrams - Preamlifier board
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Reference manual Tuning Fork Sensor Controller