High Voltage / Piezo Amplifier

A - 303 High Voltage Amplifier / Piezo Driver

The A - 303 Piezo Driver / Piezo Amplifier is a High Voltage, High Speed Piezo Driver / Linear Amplifier combined with a wideband AM/FM Modulator. It was especially designed as a Linear Amplifier / Driver for PIEZO Electric Actuators (also known as “Piezo Amplifier”), Stacks, Piezo Sheets, Bimorph Elements and other devices. It may be also used as a general purpose High Voltage Amplifier for Medical Applications (e.g. as Electrode Driver for Neurology).

The Piezo Driver / Piezo Amplifier is based on a High Voltage, High Frequency and High Current MOSFET Amplifier which is capable of driving up to ±200V (400Vptp) at ±200mA at Frequencies from DC to 450kHz.

By connecting 2 Amplifiers in Parallel or in Series, the Output Voltage and Current may be doubled to 800Vptp @ 200mA or 400Vptp @ 400mA. The Amplifier Section is Very Stable and has a Low Noise Output and a Very Low Electrical Noise.

The built-in modulator (AM or FM) enables the user to modulate the carrier frequency (adjusted on the front panel) by any input signal at the range of ±10V. This modulator can be bypassed by a switch.

This High Slew Rate Amplifier / Driver can be used for various applications requesting High Slew Rate, High Voltage and Fast Response as: Plasma Driver and Plasma Actuation, Driver for Piezo Manipulator, Optical Switching Devices, Closed Loop Feedback Systems, Vibration Control, Structural Damping Analysis, Flow Actuation and Control etc.

  1. Features:
  2. High Frequency Amplifier: DC - 1.2MHz optional
  3. Very Low Electrical Noise
  4. Low Distortion
  5. High Slew Rate: upto 400V/µSec.
  6. Input Protection: High Voltage, On/Off
  7. Output Protection: Short-circuit, Power Loss, Impedance
  1. Built in Modulator:
    1. Amplitude (AM) or Frequency (FM) Modulation
    2. High Frequency: upto 100kHz
    3. Low Distortion
    4. Adjustable Frequency, Gain, Offset

The Modulator may be turned off if not in use (only amplifier section would work)
Amplitude and Frequency modulation

  1. Block Diagram

  1. Specifications:
  2. Sync Output provides a square wave in the same phase and frequency of the modulator output (for synchronization and frequency measurement)
  3. The unit is self-cooled - no fan or noisy parts

Amplifier Section

Maximum Input Voltage:


Maximum Output Voltage:

±200V (400Vptp)

Maximum Current:



Into 1KΩ Resistive Load:
DC to 450kHz (-3dB) (DC to 1.2MHz - optional)
Into Capacitive Load:
DC to 250kHz (−3dB) (1nF)
DC to 25kHz   (−3dB) (10nF)
DC to 2.5kHz  (−3dB) (0.1µF)
DC to 250Hz   (−3dB) (1µF)
DC to 25Hz     (−3dB) (10µF)

Output Power:

40 Watt Max.

DC Gain:

20 (upto 50 optional)


Input & Output: Direct DC Coupling

DC Offset:

Adjustable to ±160V (RTO) + On/Off Switch

Input Impedance:


Slew Rate:

350V/µSec (1000V/µSec optional)

Output Impedance:


Output Noise (Input Shorted, 350kHz Bandwidth):

5mV PTP max. (1mV RMS max.)

Variable Gain Option:

0 - 10X or 0 - 20X or 0 - 40X available.
Please consult the factory regarding that option

Modulator Section

Center Frequency:

1 - 100kHz adjustable


Amplitude(AM) or Frequency(FM)


Sine Wave


0.05% Max.

Modulation Input F.S.:


Modulation Input Impedance:


Sync Output:

1Vptp, AC Coupled, 1KΩ Impedance

Amplitude Adjustment:

0.5Vptp to 20Vptp

Offset Adjustment:

±10V or 0V Fixed

Modulator Output Impedance:


The Modulator may be turned off when not in use!

AC Input

Line Input Voltage:

110/120V, 60Hz or 220/230V, 50Hz

Line Input Current:

1.3A peak


01 - High Slew Rate:


02 - Higher Gain:

Upto 50

03 - Bandwidth:

DC - 1.2MHz

04 - Variable Gain:

0 - 10X or 0 - 20X

Slew Rate option
10V Step @ Input
250V Step @ Output

Output Noise - 1.2MHz Bandwidth Option
5MHz B.W. Limit

The Standard Amplifier has Very Low Noise

Noise Level @ 350kHz BW, Input Shorted

Display set @ 2mV/div. 10µS/div.

Total Noise is less than 1mV RMS!

  1. Applications:
  2. 2 Amplifiers can be connected in Series or in Parallel in order to double the Output Voltage or Output Current. Series Connection (±400V into a Floating Load = 800Vptp)

Please note that both amplifiers must be floating (i.e. be careful not to ground them via an oscilloscope etc.)

It is also possible to double or triple the output voltage by using a special transformer. Using a transformer is possible only at high frequency (over 10kHz) and it requires more components to be added for balancing and proper termination of the load.

Parallel connection is done by adding resistors at the input and at the output. Please consult the factory for parallel connection.

In order to purchase the right amplifier to drive your load, you must calculate the peak current needed.
For Capacitive Load:
          Ipeak(A) = 2 π F C Vpeak (for a Sine Wave)
          Ipeak(A) = 4 F C Vpeak (for a triangular wave)
          Ipeak(A) = C dV / dt (for a square wave or sharp rise time)

          F = Maximum frequency (Hz.)
          C = Capacitance in Farads
          Vpeak = Maximum Voltage you need to drive your Load.
          π = 3.1415927

For Resistive Load:
          I = Vpeak / R

          Where R is the resistance of your load in ohms

The Current, Voltage and Frequency must be less or equal to the amplifier’s specifications

This Amplifier is NOT SUITABLE for driving pure Inductive Loads
(i.e. speakers, solenoides, electromagnets etc.)

You must connect your load with thick wires to minimize inductance (like speaker wires). Coaxial cable is not recommended for cables over 2m (6.5 Ft.) because the capacitance of the cable (15-50 pF/Ft) will load your amplifier at high frequencies.


The active impedance of a capacitive load is given by the equation: Z = 1 / (2 * π * F * C)
Where π = 3.1415, C in Farads, F in Hz.
The user must check that under the peak operation voltage, at maximum frequency, the current will not exceed 200mA (0.2A)


Operating Voltage is ±150V, Maximum Frequency = 10kHz, Load is 10nF
Z = 1 / (2 * 3.1415 * 10,000 * 10 * 10-9) = 1592Ω (Ohms)
150[V] / 1592[Ω] = 94[mA]
The amplifier will drive that load at an amplitude of 150V (300Vptp)

All Specifications are subject to change without a Prior Notice

For any sort of clarifications kindly contact: