PD200 - 60 Watt Voltage Amplifier

PD200 High Voltage Amplifier - Piezo Driver

The PD200 is a high bandwidth, low-noise linear amplifier for driving piezoelectric actuators. The output voltage range can be switched between bipolar or unipolar modes with a range of 200V, -50V to +150V, or +/-100V. Up to +/-200V can be achieved in the bridged configuration.

The PD200 can drive unlimited capacitive loads such as stack actuators; standard piezoelectric actuators; two wire benders; and three-wire piezoelectric benders requiring a 200V bias voltage.

Compatible Actuators
Stack Actuators 100V, 120V, 150V, 200V
Plates and Tubes up to +/-100V
Two Wire Benders up to +/-100V
Three Wire Benders 0 to 200V with 200V bias
Three Wire Benders +/-100V with +/-100V bias

The PD200 is highly user configurable with jumpers for options such as the voltage range, polarity, and gain control. Two potentiometers are also provided to limit the positive and negative voltages to any arbitrary value between zero and full range. Due to the extensive configuration options, the PD200 is suited to a wide range of applications including electro-optics, ultrasound, vibration control, nanopositioning systems, and piezoelectric motors.

There are four output connectors including Lemo 00, Lemo 0B, BNC, and screw terminals that allow the direct connection to almost any commercially available piezoelectric actuator, including those from PI, Piezomechanic, PiezoSystems, etc.

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Specifications

Electrical Specifications
Output Voltage Ranges +200V, +150V, -50V to 150V, +/-100V
RMS Current 0.57 Amps
Peak Current 2 or 10 Amps
Gain 20 V/V
Slew Rate 150 V/us
Signal Bandwidth 680 kHz
Power Bandwidth 230 kHz (200 Vp-p sine-wave)
Max Power 60 W Dissipation
Offset 0V to Full Range with front panel adjustment
Load Stable with any load
Noise 665 uV RMS (10 uF Load, 0.03 Hz to 1 MHz)
Overload Over-current protection
Voltage Monitor 1/20 V/V (BNC)
Voltage Display 4 digits, DC Voltage
Current Monitor 1 V/A (BNC)
Analog Input Signal input (BNC, Zin = 27k)
Output Connectors LEMO 00, LEMO 0B, 4mm Banana
Power Supply 90 Vac to 250 Vac

Mechanical Specifications
Environment 0 - 40 C (32-104 F), Non-condensing humidity
Dimensions 275 x 141 x 64 mm (10.8 x 5.5 x 2.5 in)
Weight 1 kg (2.2 lb)

Output Voltage Range

The desired voltage range should be identified when ordering. The following voltage ranges can be obtained with the correct combination of installed jumpers. Note that incorrect jumper settings may destroy the amplifier.

The standard output voltage range is 0V to 200V. However, the amplifier can be supplied with any voltage range by appending the order code with the voltage range code, for example, the standard configuration is PD200-V200. The voltage range jumper locations are labelled with the LP, LG, and LN prefixes on the PCB.

Voltage RangeCode LP  LG  LN LK10 & LK12
0V to +200-V200LP1LG3 Position A
0V to +150-V150LP2LG3 Position A
0V to +100-V100LP2LG2 Position A
0V to +50-V50LP2LG1 Position A
-50 to +50-V50,50LP2LG1LN1Position B
-50 to +100-V50,100LP2LG2LN2Position B
-50 to +150-V50,150LP1LG2LN2Position B
-100 to +100-V100,100LP1LG1LN2Position B

Voltage Range Configuration

The jumper settings can be modified by disconnecting the amplifier from mains power then removing the top panel to access the PCB board. Either the front or back panel can be removed by unscrewing the retaining screws then gently lifting the panel free. By placing the panel slightly below the level of the enclosure, the top panel can be slid free to expose the PCB. This procedure is reversed to reassemble the amplifier.

Voltage Limits

The output voltage range can be restricted to an arbitrary positive and negative value. There are two potentiometers that can be accessed from a pair of holes on the bottom panel. By gently turning the potentiometers fully clockwise with a 2-mm flat-head screwdriver, the full voltage range becomes available. The voltage range is reduced by turning the potentiometers anti-clockwise. The hole closest to the front panel controls the negative voltage range while the rear hole controls the positive range.

Output Current Range

The standard peak output current is +/-2 Amps; however, for applications that require very fast step changes in voltage, the amplifier can be configured in pulse mode with a 10 Amp current limit. The maximum pulse time for each mode is plotted below.

The output current range can be configured by disconnecting the amplifier from mains power then removing the front and top panel. The amplifier can be supplied preconfigured to any current range by appending the order code with the current range code, for example, the standard configuration is PD200-C2.

Peak CurrentCodePeak LimitOverload TimerMax Pulse Time
2 A-C2LK16LK19 and LK20 Out1 ms
10 A-C10LK18LK19 and LK20 In100 us

Current Range Configuration

PD200 Maximum pulse time

Maximum pulse time versus current

Power Bandwidth

Power Bandwidth Calculator

With a capacitive load, the peak load current for a sine-wave is $$ I_{pk}=\pm V_{pp} \pi C f ,$$ where \(V_{pp}\) is the peak-to-peak output voltage, \(C\) is the load capacitance and \(f\) is the frequency. Given a peak current limit \(I_{pk}\), the maximum frequency is therefore \(f=I_{pk}/V_{pp} \pi C\). However, the PD200 is protected by both peak and average current limits. The average current \(I_{av+}\) is defined as the average positive or negative current. For example, for a sine-wave $$I_{av+} = \frac{1}{2\pi} \int_{0}^{\pi} I_{pk} \sin(\theta) d\theta = \frac{I_{pk}}{2\pi} \left[-\cos\right]_0^\pi = \frac{I_{pk}}{\pi} .$$ Therefore, for a sine-wave \(I_{av+}=I_{pk}/\pi\). Since the average current limit of the PD200 is fixed at \(I_{av+}=0.26\), the maximum frequency sine-wave, or power bandwidth of the PD200, is equal to $$ f = \frac{0.26}{V_{pp} C}.$$ The above result is true for any periodic waveform such as triangular signals. The RMS current for a sine-wave can also be related to the average current, $$ I_{av+} = \frac{\sqrt{2}}{\pi} I_{rms} .$$

The power bandwidths for a range of load capacitance values are listed below.

LoadPeak to Peak Voltage
Cap200V150V100V50V
No Load230 kHz310 kHz470 kHz520 kHz
10 nF130 kHz173 kHz260 kHz520 kHz
30 nF43 kHz58 kHz87 kHz173 kHz
100 nF13 kHz17 kHz26 kHz52 kHz
300 nF4.3 kHz5.8 kHz8.7 kHz17 kHz
1 uF1.3 kHz1.7 kHz2.6 kHz5.2 kHz
3 uF430 Hz570 Hz870 Hz1.7 kHz
10 uF130 Hz170 Hz260 Hz520 Hz
30 uF43 Hz57 Hz87 Hz170 Hz

Power Bandwidth versus Load Capacitance

In the following figure, the maximum frequency periodic signal is plotted against the peak-to-peak voltage.

PD200 Power bandwidth

Power bandwidth versus voltage and load capacitance

Small Signal Bandwidth

PD200 Small signal frequency response

Small signal frequency response

Load Cap.Bandwidth
No Load684 kHz
10 nF759 kHz
30 nF720 kHz
100 nF388 kHz
300 nF172 kHz
1 uF60 kHz
3 uF21 kHz
10 uF6.4 kHz
30 uF2.4 kHz
110 uF940 Hz

Small signal bandwidth versus load capacitance (-3dB)

Noise

The output noise contains a low frequency component (0.03 Hz to 20 Hz) that is independent of the load capacitance; and a high frequency component (20 Hz to 1 MHz) that is inversely related to the load capacitance. Many manufacturers quote only the AC noise measured by a multimeter (20 Hz to 100 kHz) which is usually a gross underestimate.

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 5. The RMS value is 650 uV with a peak-to-peak voltage of 4.3 mV. The noise level is approximately equal to the least significant bit of a 16-bit digital-to-analog converter.

PD200 low frequency noise

Low frequency noise from 0.03 Hz to 20 Hz. The RMS value is 650 uV, or 4.3 mVp-p

The high frequency noise (20 Hz to 1 MHz) is listed in the table below versus load capacitance. The total noise from 0.03 Hz to 1 MHz can be found by square summing the RMS values, that is $$ \sigma = \sqrt{ \sigma_{LF}^2 + \sigma_{HF}^2 } .$$

Load Cap.BandwidthHF Noise RMSTotal Noise RMS
No Load684 kHz240 uV698 uV
10 nF759 kHz241 uV698 uV
30 nF720 kHz243 uV699 uV
100 nF388 kHz234 uV696 uV
300 nF172 kHz171 uV677 uV
1 uF60 kHz133 uV668 uV
3 uF21 kHz115 uV665 uV
10 uF6.4 kHz112 uV665 uV
30 uF2.4 kHz98 uV662 uV
110 uF940 Hz85 uV660 uV

RMS noise versus load capacitance (0.03 Hz to 1 MHz)

Input and Offset Configuration

The input stage is normally non-inverting; however, it can be configured as inverting by changing LK14 and LK15 to their "B" position. The default jumper position is "A" which is marked with a white bar on PCB overlay. The amplifier can be supplied with an inverting input by appending the order code with -INV.

Input ConigurationCodeLink Positions
Non-inverting (default) LK14 and LK15 both "A"
Inverting-INVLK14 and LK15 both "B"

Input polarity configuration

The input offset source is also configurable. When LK21 is in the "B" position, the offset is derived from the on-board trim-pot R12, which is adjustable from zero to full-scale. The default configuration for LK21 is in the "A" position where the offset voltage is derived from the front-panel potentiometer.

The standard offset voltage range is from zero volts to full-scale; however, for applications that require negative offset voltages, LK13 can be moved from the "A" to "B" position. In the "B" position, the offset range is from -100V to full-scale.

Offset ConfigurationCodeLink Positions
0V to +200V Range (default) LK13 "A" Position
-100V to +200V Range-OR2LK13 "B" Position
Front panel source (default) LK21 "A" Position
PCB trim-pot source-OS2LK21 "B" Position

Offset voltage source configuration

Bridged Mode

In bridged mode, two amplifiers are connected in series to double the output voltage range and power. To obtain +/-200V at the load, the amplifiers are configured as illustrated below. Both amplifiers are configured in the +/-100V range and the lower amplifier is also inverting. A +/-5V signal applied to both inputs will develop +/-200V at the output.

PD200 Bridged Mode

Bridged configuration for obtaining +/-200V

Overload Protection

The Shutdown indicator will illuminate during a shutdown caused by an average current overload. During shutdown, the amplifier output current is limited to a few mA and may float to the high or low voltage rail if the load impedance is high or capacitive.

When the amplifier is turned on, the overload protection circuit is engaged by default and will take approximately three seconds to reset.

Output Connections

An actuator can be connected to the amplifier by either screw terminals or the LEMO 00, LEMO 0B, or BNC connectors. The recommended connectors are listed below. The full connector part number will depend on the diameter of the cable and desired strain relief.

OutputConnectorManufacturerPCB Connector
BNCAny BNC ConnectorTE1-1634613-0
Terminals20020004-D041B01LFFCI20020110-D041A01LF
LEMO 00FFA.00.250LEMOEPL.00.250
LEMO 0BFGG.0B.302LEMOEPG.0B.302

Output connectors

The LEMO 0B connector is recommended in high power applications. Preassembled LEMO cable assemblies are available from www.PiezoDriveOnline.com

The plug-in screw terminal has contacts for the output voltage, ground, and the positive and negative high-voltage supply rails, which are useful when driving piezoelectric bender actuators.

PD200 Screw terminal connections

PD200 Screw terminal connections

Bender actuators can be driven with a single bias voltage, for example 200 V, or bipolar bias voltages, for example +/-100 V. The 200 V unipolar configuration is illustrated below.

Piezoelectric bender actuator connection to the PD200

Piezoelectric bender actuator connection to the PD200

Enclosure

The PD200 enclosure has a side air intake and rear exhaust. These vents should not be obstructed.

The PD200 amplifiers can be rack-mounted in a three channel arrangement as shown below. The rack panel (19-inch X 2U) is supplied separately and requires some user assembly to mount between one and three channels. The rack order code is PD200-RackPanel.

19 inch rack panel for PD200

19 inch rack panel for PD200

Warranty

PiezoDrive amplifiers are guaranteed for a period of 3 months. The warranty does not cover damage due to misuse or incorrect user configuration of the amplifier.