PX200 Power Amplifier
Manual and Specifications
Hardware Version 5

Revision History
Date

Revision

By

Changes

15/05/22 1

KB

Document published

20/05/22 2

KB

Voltage range table updated

26/06/23 3

KB

Pulse mode description updated

PX200 V5 Manual

1

26/06/2023

Contents
1

Introduction ....................................................................................................................................... 3

2

Warnings / Notes ............................................................................................................................... 33

Output Voltage Ranges ...................................................................................................................... 44

Output Current .................................................................................................................................. 55Power Bandwidth .............................................................................................................................. 5

6

Pulse Current Option ......................................................................................................................... 7

7

Specifications ..................................................................................................................................... 9

8

Small Signal Bandwidth ................................................................................................................... 10

9Noise ................................................................................................................................................ 11

10

Front Panel .................................................................................................................................... 12

11

Signal Path ..................................................................................................................................... 13

12

Voltage Limits................................................................................................................................ 14

13

Bias Outputs and Piezo Benders ................................................................................................... 14

14

Overload and Shutdown ............................................................................................................... 14

15

Bridged Mode ............................................................................................................................... 16

16

Rack Mounting .............................................................................................................................. 17

17

Delivery Contents .......................................................................................................................... 17

18

Warranty ....................................................................................................................................... 17

PX200 V5 Manual226/06/2023

1 Introduction
The PX200 is a low-noise high-current linear amplifier for driving piezoelectric actuators and otherloads. The output voltage range can be unipolar, bipolar, or asymmetric from 50V to 200V. Refer tothe specifications table for the available output voltage ranges. Two amplifiers can be connected inbridge-mode to provide up to +/-200V or +400V. The PX200 has a high output current up to 13 Amps
peak and is well suited to precision applications that require high power and frequency.
The PX200 can drive any load impedance including unlimited capacitive loads such as stack actuators;
standard piezoelectric actuators; two wire benders; and three-wire piezoelectric benders requiring abias voltage. Bias voltages can be generated using two auxiliary outputs linked to the power supply
voltages.
A range of front panel controls provide maximum application flexibility, these include input signal
inversion, variable gain, DC offset, and variable voltage limits. A 9-pin DSUB connector on the front
panel includes signals for the input, voltage monitor, current monitor, shutdown monitor, andshutdown command. A four-digit LCD screen also displays the DC voltage.
The output connectors include BNC, LEMO 00, LEMO 0B.302, and plug-in screw terminals. The PX200
is suited to a wide range of applications including electro-optics, ultrasonics, vibration control,
nanopositioning systems, and piezoelectric motors.
Compatible Actuators
Stack Actuators

Up to +200V

Plates and Tubes+/-100V or +200V

Two Wire Benders+/-100V or +200V

Three Wire Benders

Up to +200V with +200V bias, or +/-100V with +/-100V bias

2 Warnings / Notes
This device produces hazardous potentials and requires suitably
qualified personnel with an observer trained in first-aid training. Do not
operate the device when there are exposed conductors.

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3 Output Voltage Ranges
The output voltage range is specified when ordering. The standard voltage ranges and associatedcurrent limits are listed below. Since the PX200 has front panel controls for reducing the positive andnegative output voltage range, choose a range equal to or slightly greater than required.
Negative Positive
RMS
Peak
Voltage Voltage Current Current(Volts)(Volts) (Amps) (Amps)
0
200
1.6
3

Pulse
Current
[1]
9

Gain
[2]

Var
[3]

Order
Code

20

A

PX200-P200

0

150

2.1

4

10

15

A

PX200-P150

-50

150

1.6

3

9

15

A

PX200-N50-P150

-50

100

2.1

4

10

10

A

PX200-N50-P100

-100

100

1.6

3

9

10

A

PX200-N100-P100

-100

50

2.1

4

10

10

A

PX200-N100-P50

-100

0

3.1

6

13

10

A

PX200-N100

-150

0

2.1

4

10

15

A

PX200-N150

-200

0

1.6

3

9

20

A

PX200-N200

0

175

1.8

3

10

20

B

PX200-P175

-25

150

1.8

3

10

15

B

PX200-N25-P150

-25

100

2.7

4

10

10

B

PX200-N25-P100

-75

100

1.8

3

10

10

B

PX200-N75-P100

-75

50

2.7

4

10

10

B

PX200-N75-P50

0

125

2.7

4

10

15

D

PX200-P125

-25

125

2.1

4

10

15

D

PX200-N25-P125

-75

75

2.1

4

10

10

D

PX200-N75-P75

0

100

3.1

6

13

10

E

PX200-P100

0

75

4.1

6

13

10

E

PX200-P75

0

50

5.3

9

13

10

E

PX200-P50

0

25

5.3

9

13

10

E

PX200-P25

-25

75

3.1

6

13

10

E

PX200-N25-P75

-25

50

4.1

6

13

10

E

PX200-N25-P50

-25

25

5.3

9

13

10

E

PX200-N25-P25

-50

50

3.1

6

13

10

E

PX200-N50-P50

-50

25

4.1

6

13

10

E

PX200-N50-P25

-50

0

5.3

9

13

10

E

PX200-N50

-75

0

4.1

6

13

10

E

PX200-N75

-100

0

3.1

6

13

10

E

PX200-N100

Table 1. Preferred voltage range configurations.
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Notes:[1] – Refer to Section 6 for details on the pulse current limit[2] – The gain can be increased by up to another factor of 10 using the front panel control[3] – The variant is the hardware version required for the chosen configuration

4 Output Current
The peak and RMS output current is listed in Table 1. The RMS current limit determines the maximum
frequency that is achievable with a capacitive load. A calculator for the maximum operating
frequency is provided in Section 5.
During short-circuit the output current is limited to the rated maximum. The peak current can be
drawn for up to five milliseconds before the output is disabled for three seconds. The average current
limit has a time-constant of ten milliseconds and is reset 50 milliseconds after a previous current
pulse. This behaviour is described in Section 13.
Higher peak currents are achievable with the PULSE option, which is described in Section 6.

5 Power Bandwidth
Launch Online Power Bandwidth Calculator

The online power bandwidth calculator estimates the highest achievable frequency with a capacitive
load impedance. The calculator considers the current limit, slew-rate, output impedance, and smallsignal bandwidth.
With a capacitive load, the maximum operating frequency due to the RMS current limit is𝑓𝑚𝑎𝑥 =

𝐼𝑟𝑚𝑠 √2,
𝑉𝑝𝑝 𝐶𝜋where 𝐼𝑟𝑚𝑠 is the current limit, 𝑉𝑝𝑝 is the peak-to-peak output voltage, 𝐶 is the load capacitance. The
above equation is also true for any periodic waveform, including triangle waves and square waves.
The ‘power bandwidth’ is the maximum frequency at full output voltage. When the amplifier output
is open-circuit, the power bandwidth is limited by the slew-rate; however, with a capacitive load, themaximum frequency is limited by the RMS current and load capacitance. The power bandwidth for arange of capacitive loads is listed below.

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Load

50 Vp-p

75 Vp-p

100 Vp-p

125 Vp-p

150 Vp-p

175 Vp-p

200 Vp-p

10 nF

222930*148620*111465*89172*

74310*

63694*

55732*

30 nF

222930*148620*111465*89172*

74310*

63694*

55732*

100 nF

222930*148620*111465*89172*

62000

45714

35000

300 nF

160000

82667

46667

32000

20667

15238

11667

1 uF

48000

24800

14000

9600

6200

4571

3500

3 uF

16000

8267

4667

3200

2067

1524

1167

10 uF

4800

2480

1400

960

620

457

350

30 uF

1600

827

467

320

207

152

117

Table 2. Maximum frequency (Hz) versus load capacitance and output voltage spanIn the above table, the frequencies limited by slew-rate are marked with an asterisk. The slew-rate isapproximately 35 V/uS which implies a maximum frequency of𝑓 𝑚𝑎𝑥 =PX200 V5 Manual

35 × 106𝜋𝑉𝑝𝑝

626/06/2023

6 Pulse Current Option
The PULSE current option provides a higher peak current for approximately 150 us instead of thestandard 5 ms. This option is useful in specialty applications that require fast, small changes in the
output voltage with large capacitive loads. The achievable step change in voltage is,
Δ𝑉 =𝐼𝑝𝑘 𝑡𝑝𝑢𝑙𝑠𝑒
𝐶𝑙𝑜𝑎𝑑

where, Δ𝑉 is the step change in Volts, 𝐼𝑝𝑘 is the pulse current limit of the amplifier, and 𝑡𝑝𝑢𝑙𝑠𝑒 is the
maximum pulse time of the amplifier, listed below. With large capacitive loads, it may not be possible
to step between the minimum and maximum output voltage. The maximum capacitance where a fullrange step can by sustained is approximately,
𝐶𝑚𝑎𝑥 =

𝐼𝑝𝑘 𝑡𝑝𝑢𝑙𝑠𝑒
Δ𝑉

The PULSE option provides approximately three times higher peak-current, but less than one-tenth ofthe permissible overload time compared to the standard option. Therefore, the PULSE option
provides approximately one-third of the Δ𝑉 and 𝐶𝑚𝑎𝑥 compared to the standard version and should
only be selected for applications where the higher peak current is worth the reduction in permissible
overload time.
With waveforms that do not require step changes in voltage, such as sinusoidal and triangular signals,
the standard configuration is preferrable. At frequencies below 1kHz, the PULSE option will result in
lower-than-expected power bandwidth as the signal rise time will exceed 500us and may trigger theovercurrent protection.
The pulse current limits for each configuration are listed in Table 1 and summarized in Table 3. The
output voltage span is the peak-to-peak output voltage range, e.g. the voltage span for the -50V to+150V range is 200V.

Output Voltage Span

Pulse Current

Pulse Time

Cmax (full step)

200 Vp-p

9A

150 us

6.7 uF

175 Vp-p

10 A

155 us

8.8 uF

150 Vp-p

10 A

180 us12 uF

125 Vp-p

10 A

236 us18 uF

100 Vp-p

13 A

211 us27 uF

75 Vp-p

13 A

286 us

49 uF

50 Vp-p

13 A

378 us

98 uF

25 Vp-p

13 A

378 us196 uF

Table 3. Maximum peak current and duration in the pulse configuration. 𝑪𝒎𝒂𝒙 is the maximum
capacitance where the full voltage range can be stepped.
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The maximum pulse duration versus peak current is described in Figure 1. The pulse current option
can be ordered by appending the order code with “-PULSE”, e.g. “PX200-P200-PULSE”.

Figure 1. Maximum pulse duration versus peak current for each voltage span

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7 Specifications
The voltage, current, and gain specifications are listed in Table 1. Other specifications that arecommon to all configurations are listed below.
Specification

Value

Slew Rate

35 V/usSignal Bandwidth

390 kHzMax Power

140 W Dissipation

Load

Any

Noise

150 uV RMS (10uF Load, 0.03 Hz to 1 MHz)

Protection

Continuous short-circuit, thermal

Voltage Monitor

1/20 V/V

Current Monitor

1.5 V/A if peak current is 6 Amps or less
0.5 V/A if peak current is greater than 6 Amps

Input Impedance

48.7 kOhms

Output Impedance

1.5 Ohms

Output Connectors

LEMO 0B, LEMO 00, Screw Terminals, BNC

Power Supply

90 Vac to 250 Vac

Environment

0-40 C (32-104 F) Non-condensing humidity

Dimensions

212 x 304.8 x 88 mm (8.35 x 12 x 3.46 in)

Weight2 kg (4.4 lb)

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8 Small Signal Bandwidth
The small-signal frequency response and -3 dB bandwidth is described in Figure 2 and Table 4.

Magnitude (dB)30

100 nF
1 uF

20

10 uF

10 nF

10
0

30 uF

-10
-20
3
10

4

3 uF
5

10

10

300 nF

30 nF
6

10

100
50

Phase (deg.)

0
-50
-100
-150
-200
-250
3

10

4

5

10

10
Frequency (Hz)6

10

Figure 2. Small signal frequency response for a range of load capacitances.

Load Capacitance

Bandwidth

10 nF

393 kHz

30 nF

431 kHz100 nF367 kHz300 nF

208 kHz

1 uF

88 kHz

3 uF

30 kHz10 uF

9.3 kHz30 uF

3.7 kHz110 uF

1.3 kHz

Table 4. Small signal bandwidth versus load capacitance (-3dB)

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9 Noise
The output voltage noise contains a low frequency component (0.03 Hz to 20 Hz) that is independentof the load capacitance; and a high frequency (20 Hz to 1 MHz) component that is approximately
inversely proportional to the load capacitance.
The noise is measured with an SR560 low-noise amplifier (Gain = 1000), oscilloscope, and Agilent
34461A Voltmeter. The low-frequency noise is plotted in Figure 3. The RMS value is 120 uV with apeak-to-peak voltage of 600 uV.

Figure 3. Low frequency noise from 0.03 Hz to 20 Hz
The high frequency noise (20 Hz to 1 MHz) is listed in the table below versus load capacitance. The
22
total RMS noise from 0.03 Hz to 1 MHz is found by summing the RMS values, that is 𝜎 = √𝜎𝐿𝐹
+ 𝜎𝐻𝐹.
For a load capacitance of less than 1 uF, the noise is primarily broadband thermal noise; however, fora capacitance of greater than 1 uF, the noise is primarily due to low-frequency noise.

Load

Bandwidth

HF Noise RMS

Total Noise RMS

10 nF

393 kHz530 uV543 uV

30 nF

431 kHz586 uV598 uV

100 nF367 kHz689 uV699 uV

300 nF

208 kHz452 uV468 uV

1 uF

88 kHz261 uV287 uV

3 uF

30 kHz106 uV160 uV

10 uF

9.3 kHz56 uV132 uV30 uF

3.7 kHz52 uV131 uV

100 uF

1.3 kHz47 uV

129 uV

Table 5. RMS noise versus load capacitance (0.03 Hz to 1 MHz)PX200 V5 Manual

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10 Front Panel

ControlType

Function

PowerPower On/Off

Overload LED

RED when the amplifier is disabled or in an overload statePower LED

GREEN when the power is on

Input

Input

Input signal (±10V max, protected up to +/-20V)

Invert switch

Multiplies the input signal by -1 in the upward position

Gain switch

Adds additional gain to the input signal when in the upward position

Gain pot

Clockwise rotation increases the additional gain (up to a factor of 10)

Offset knob

Single turn potentiometer for DC offset

Offset pot

Multiple turn potentiometer for DC offset

Offset switch

Selects between the offset sources, or zero in the middle position

Voltage Limits

Limits the maximum negative and positive output voltage

Voltage Monitor

Output

The measured output voltage, scaled by 1/20

Current Monitor

Output

The measured output current, 1.5 V/A or 0.5 V/A (See Section 0)

Bias-

Output

DC Bias connected to the negative high-voltage power supply rail

Bias+

Output

DC Bias connected to the positive high-voltage power supply rail

GroundOutputGround, connect to the load negative terminal

OutputOutputAmplifier output, connect to the load positive terminal

LEMO 00 Output

Output

EPL.00.250 connector, suits LEMO FFA.00.250 cable plug

LEMO 0B Output

Output

FGG.0B.302 connector, suits LEMO FGG.0B.302 cable plug

BNC Output

OutputSuits male BNC cable plug

DC Output Volt.

Display showing average output voltage

The mating connector for the 4-way screw terminal connector is OQ0432510000G.
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The screw terminals or LEMO 0B.302 connector are recommended for applications requiring morethan 1 Amp RMS output current. Preassembled LEMO cable assemblies (e.g. PD-0B302-W-120) areavailable from www.PiezoDrive.com
The auxiliary signals connector is a 9-way DSUB receptacle which suits any 9-way male DSUB plug.
The signals and pin layout are shown in Figure 4 and Table 6.

5

3

4
9

7

8

1

2
6

Figure 4. Front view of auxiliary signals connector

SignalPinFunction

Input+

1

Input signal

Input-

2

Ground for input signal

Voltage Monitor

3

Voltage monitor

Current Monitor

4

Current monitor

Ground5

GroundShutdown

6+2V to +20V disables the amplifier

Shutdown Monitor

7+5V when the amplifier is shutdown

NC

8, 9

Not connected

Table 6. Auxiliary signals pinout

11 Signal Path
Offset Knob
zero
Offset Pot
OffsetSwitchGain Pot
Input

OutputVoltage
Limits-1

InvertSwitchExtra Gain
SwitchK
Power Amplifier
See Table 1 for Gain

Figure 5. Signal path with switches in default positions.
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12 Voltage Limits
The output voltage range can be restricted to an arbitrary positive and negative value using two
potentiometers on the front panel. To set the voltage limit:• Remove loads connected to the outputs• Apply a 100-Hz sine wave to the input of channel 1 with an amplitude that covers the full rangeof the amplifier. For example, with a 0V to +200V model, apply a 0V to +10V input.
• Measure the output voltage of channel 1 with an oscilloscope and confirm the full voltage
range is achieved. If there is any clipping of the sine wave, the voltage limits may have alreadybeen set, and may need resetting by winding the potentiometers in the direction of thearrows.
• To limit either the negative or the positive voltage, turn the potentiometer in the opposite
direction to the arrow, until the voltage is limited to the desired level.

13 Overload and Shutdown
The amplifier is protected against short-circuit, over-current, and excessive temperature. During
these conditions, the front panel overload indicator will illuminate, and the Shutdown Monitor signal
is +5V.
During an overload or shutdown state, the output is partially disabled and may float at approximately
50% of the voltage range.
When the amplifier is switched on, the overload protection circuit is engaged by default and clears
after three seconds.
The amplifier can be shut down by an external source by applying a voltage of between +2V and +24V
to the Shutdown input. The impedance of the shutdown input is approximately 5 kΩ.

14 Bias Outputs and Piezo Benders
The bias outputs are labelled HV+ and HV- on the front-panel screw terminals. The output voltages
are fixed at the maximum output voltages of the amplifier and are not affected by the voltage limit
potentiometers. For example, a PX200-N100-P100 (with a +/-100V output range) will output +100V
and -100V on HV+ and HV- respectively. For amplifier configurations where the HV- output is zero(e.g. PX200-P200), it is preferable to use ground rather than the HV- output.
The bias outputs provide a small DC output current of approximately 30mA; however, they cansource or sink large AC currents, which is ideal for driving piezoelectric actuators. Bender actuators
can be driven with a single or dual bias voltage.

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The most common bender actuators are parallel-poled and driven using the ‘biased unipolar’ or‘three-wire’ configuration [1], as shown in Figure 6.
PX200-P150
HV+
0 to 7.5V

CH1 InCH1 Out+150 Vdc

Parallel-poled bender, e.g.
Thorlabs PB4NB2W or
PiezoDrive BA6020

0 to +150V

𝛿
GroundGroundFigure 6. Parallel-poled bender driven in the biased unipolar configuration [1].
A zero volt input results in +150V across the top piezo layer and maximum upward deflection. A 7.5V
input results in +150V across the bottom piezo layer and maximum downward deflection. The
deflection 𝛿 can be represented by𝛿=𝑉𝑖𝑛 − 7.5/2
𝛿𝑝𝑝7.5

where 𝛿𝑝𝑝 is the peak-to-peak displacement of the bender.
To reduce the maximum DC voltage, a negative bias voltage can be used, as shown in Figure 7.
PX200-N100-P100
HV+
+/-5V

CH1 InCH1 Out+100 Vdc

200V parallel-poled bender,
e.g. Noliac CMBR02+/-100 V𝛿
HV--100 Vdc

Figure 7. 200V Parallel-poled bender driven with dual bias sources.
In Figure 7, the deflection is
𝛿=

𝑉𝑖𝑛
𝛿
10 𝑝𝑝

where 𝛿𝑝𝑝 is the peak-to-peak displacement of the bender.
References[1]

A New Electrical Configuration for Improving the Range of Piezoelectric Bimorph Benders; S. A.
Rios, A. J. Fleming; Sensors and Actuators A: Physical, 2015.

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15 Bridged ModeIn bridged mode, the load is connected between the outputs of two amplifiers, which doubles theoutput voltage span and power. Grounded loads cannot be driven using bridged mode. Care should
be taken not to connect the negative side to ground accidentally, for example, by using a grounded
oscilloscope probe.
Figure 8 shows how two amplifiers are connected to achieve +/-200V across a load. A +/-10V signal isapplied to both amplifiers, and the bottom amplifier is configured in inverting mode. The total voltage
across the load is +/-200V and the effective gain is twice the gain of a single amplifier. Common
bridged-mode configurations are listed in Table 7.
The current limits in bridge mode are identical to normal operation. The power bandwidth calculator
can also be used for predicting bridge-mode performance by entering the total voltage across theload. For the example in Figure 8, the total peak-to-peak output voltage is 400V. When entering thisvalue to the calculator, an error will be shown since 400V is greater than the voltage span of a single
amplifier; however, the calculator output is remains valid.
±10V

±100V

Non-inverting
SignalGenerator

10

Voltage across load
±200V

+

PX200-N100-P100-10Inverting
PX200-N100-P100±100V

Figure 8. Bridge mode configuration for obtaining ±200V
Load Voltage

RMS Current

Non-Inverting Amp

Inverting Amp

±200V

1.5 A

PX200-N100-P100

PX200-N100-P100

±100V

3.1 A

PX200-N50-P50

PX200-N50-P50

0V to 200V

3.1 A

PX200-P100

PX200-N100

0V to 300V

2.1 A

PX200-P150

PX200-N150

0V to 400V

1.5 A

PX200-P200

PX200-N200

Table 7. Common bridge-mode configurations

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16 Rack Mounting
The PX200 can be installed in a 19-inch x 2U rack space using the single unit rack kit(order code: SingleRackKit-2U).
Two amplifiers can also be installed in a side-by-side configuration using the double unit rack kit(order code: DoubleRackKit-2U). The double rack kit is assembled in the factory and includes coupling
screws for the enclosure, the same handles as the single rack kit, andFigure 9. Single rack kit, showing the amplifier on left, and the rack adaptor on right.

17 Delivery Contents• PX200 amplifier with plug-in screw terminal installed• IEC C13 power cable, suited to the shipping destination

18 Warranty
PiezoDrive amplifiers are guaranteed for 12 months from the date of delivery. The warranty does notcover damage due to misuse.

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