Reference manual · Reference manual Tuning Fork Sensor Controller 7 2. Knobs and connectors The...

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.

Reference manual:Tuning Fork Sensor Controller

5

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).


6

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.


7

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.


8

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

-


9

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


10

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


11

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.


12

■ 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”


13

■ 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.


DC 1.2345 V

MultimeterPreamplifier board


55’000.0055’000.00

Sine wave generator withNO frequency sweep mode


Selector to “Amplitude”“Tuning fork sensor”or “A-Probe”


14

■ 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


15

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.


Oscilloscope

Preamplifier board

Selector to “Int.”

Selector to “Drive signal”

Scanning probe system(z-feed back)



16

■ 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”.


17

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%


18

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.


Preamplifier board


55’000.00

Selector to “Amplitude”

Sine wave generator Scanning probe system(z-feed back)



19

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.


20

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


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


22

Appendix 3: Circuit Diagrams - Preamlifier board

www.NanoAndMore.com

Reference manual Tuning Fork Sensor Controller

Reference manual · Reference manual Tuning Fork Sensor Controller 7 2. Knobs and connectors The...

Documents

Transcript of Reference manual · Reference manual Tuning Fork Sensor Controller 7 2. Knobs and connectors The...