• DOA series
  • DOA series

DOA series

Ultra High Speed Response Four-Quadrant Bipolar Power Supplies

  • Max Output Voltage: ±75V or ±150V
  • Max output power:
    75W to 300W
  • Frequency bandwidth:
    DC to 1MHz
  • Wonder Broadband

Stable operation is possible regardless to loads with massive broadband and high speed response of DC to 1MHz Maximum and four-quadrant output.

DOA series are four-quadrant bipolar power supplies realized broadband and ultra high speed response of DC to 1 MHz maximum. They are best fitted to transient response tests using effectively this feature of massive high speed response.
And, with the four-quadrant behavior usable as DC power supplies or DC electronic loads, they are applicable to various loads such as inductive loads as transformer, capacitive loads as capacitor or motors, piezo elements.
They are products with excellent general-purpose property able to output maximum current at DC output.


  • High speed response of DC to 1 MHz or 500 kHz is realized.
  • Four-quadrant behavior possible to source and sink current.
  • DC bias function is equipped as standard.
  • It is possible to output maximum current at DC output.
  • Reassurance and safety design equipped overvoltage protection, overcurrent protection and output short-circuit protection.


  • Evaluation tests for inductive loads such as coils and transformers.
  • Voltage fluctuation tests for electric elements of cars.
  • Evaluation tests for capacitive loads such as capacitors or display panels.
  • Ripple test for capacitors.
  • Evaluation tests of various motors.
  • Evaluation tests of relative equipment to solar batteries.
  • Drive of piezo elements. etc.
This product is not designed for charge and discharge of battery. Please contact nearby sales if unit is used for charge and discharge application.


Each model will be brought to the market sequentially. Please confirm our sales staff the detail period of sale for models you want prior to order.

Model Maximum Output Frequency bandwidth (-3 dB) Input Voltage Input Current
Voltage [V] Current [A] Power[W] At maximum oscillation. @1115 V @230 V
DOA75-1 ±75 ±1 75 DC to 1 MHz 100 Vac ± 10%
240 Vac ±10%
50 Hz/60 Hz
3 A 1.5 A
DOA75-2 ±2 150 4 A 2 A
DOA75-4 ±4 300 6 A 3 A
DOA150-1 ±150 ±1 150 DC to 500 kHz 4 A 2 A
DOA150-2 ±2 300 6 A 3 A


About protection functions

OVP (Overvoltage Protection)
This unit is equipped overvoltage protection and output voltage is limited about 120% of rating and the load is protected at abnormal.
OCP (Overcurrent Protection)
This unit is equipped overcurrent protection and output current is limited about 120% of rating and the power supply and the load are protected at overload.

High Speed Eddy Current Protection

This unit is equipped two kinds of eddy current protections,high speed eddy current protection circuit to limit pulse current and overcurrent protection circuit to limit stationary current.
The above mentioned overcurrent protection is to limit stationary current and its response speed is about 1msec. Another circuit to limit current of high speed response type is added separately and it restricts pulse current to about 2 times of rating at rectangular wave or capacitive load.

High Speed Eddy Current Protection

About the range of output

This unit is a bipolar power supply possible to operate in four-quadrant behavior. It is able to source or sink current in the ranges as shown on the following figure.

  • Vo max: rated output voltage
  • Io max: rated output current
A legend About the range of output


For details, download the datasheet below.


-LN: Power Failure Protection is not equipped

-LVs: The output range is shifted

This knob is attached on the front panel.

The output range is shifted.
Shiftiong following 3 ranges is possible for ±75 V output models.
(L) -125 V to +25 V
(M) -75 V to +75 V
(H) -25 V to +125 V
Shifting following 3 ranges is possible for ±150 V output models.
(L) -250 V to +50 V
(M) -150 V to +150 V
(H) -50 V to +250 V

How to Order

To order, please add the above option codes to the tail of the model number.

[Example] DOA150-2-LNVs (alphabetical order)


For details, download the datasheet below.

Tech Notes

Capacitive Load

When a capacitive load is more than 100 pF (including a stray capacitance of output wire), the resonance in the output may occur. In that case, install 100-ohm (@0.1 μF) to 1000-ohm (@1000 pF) of high voltage resistance in the output in series. Please note that the frequency band will be limited as the formula written in the right figure when an amplifier is used with a capacitive load.
In addition, when an amplifier is used for the use such as a corona discharge, the current which is higher than rating will flow and it will affect the amplifier badly. In this case, as well as the time to use an amplifier with a capacitive load, please install the output resistance and limit the current.

* Please avoid continuous inputting of high frequency signal which reduces output frequency of an amplifier. An amplifier will be broken because of increase of internal loss.

This image explains frequency band when a capacitive load is connected.

Read more


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Bipolar power supplies/High voltage Amplifiers