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 wide band 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 (for example, as electode 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 (400V ptp) at ±200mA at frequencies from DC to 450 kHz.

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-1.2 MHz optional
  3. Very Low Electrical Noise
  4. Low Distortion
  5. High Slew rate-up to 400 Volt/microsecond
  6. Input protection-High Voltage, On/Off
  7. Output protection - Short-circuit, Power loss, Impedance
  • Built in Modulator:
  • Amplitude(AM) or Frequency(FM) modulation
  • High Frequency - up to 100 kHz.
  • Low distortion
  • 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 1K 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 Maximum

    DC Gain

    20 (up to 50 optional)


    Input & Output: Direct DC Coupling

    DC Offset

    Adjustable to ±8 Volts + On/Off Switch

    Input Impedence


    Slew Rate

    350V/ µSec (1000V/µSec optional)

    Output Impedence


    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

    Modulaltor Section:

    Center Frequency

    1 - 100kHz adjustable


    Amplitude(AM) or Frequency(FM)


    Sine Wave


    0.5% maximum

    Modulation Input F.S.

    ±10 V

    Modulation Input Impedance

    10 K

    Sync Output

    1V ptp, AC coupled, 1K Impedance

    Amplitude Adjustment

    0.5V ptp to 20V ptp

    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



    High Slew Rate 1000V/µSec


    Higher Gain Up to 50


    Bandwidth DC-1.2 MHz


    Variable Gain 0-10X or 0-20X - No Charge

    Slew Rate option

    10V Step @Input

    250V Step @Output

    Output Noise - 1.2 MHz. Bandwidth Option

    5MHz B.W. Limit

    The Standard amplifier has very low noise

    Noise level @ 350 KHz. BW, input shorted

    Display set @2 mV/div. 10uS/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 = 800V ptp)

    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 tripple the output voltage by using a special transformer. Using a transformer is possible only at high frequency (over 10 KHz.) 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 calulate 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)=1592 Ohms
    150[V]/1592[Ohm]=94[mA] ===> The amplifier will drive that load at an amplitude of 150V (300V ptp)

    For any sort of clarifications kindly contact: