• DOEF series | Bipolar power supply (Low Voltage Amplifiers) | Matsusada Precision
  • DOEF series | Bipolar power supply (Low Voltage Amplifiers) | Matsusada Precision


High speed response of DC to 200kHz.
Ultimate in accurate sequence operation.
Extremely sophisticated quality to output programmed waveform.

  • Max Voltage: ±20V to ±60V
  • Max Power: 1200W


DOEF series are four-quadrant power supplies possible to source and sink current. They can be applied widely according to usage, from transient response tests to various evaluation tests. That realizes a high-speed response of DC to 200 kHz (at constant voltage mode) and can generate basic waves such as sine waves, rectangular waves, and customized waves by the embedded function generator.

And, as they also provide sequence function as standard, you can program output patterns in detail. Moreover, as This bipolar power supply can make their generation of wave and set sequence memories all with the simplified operation on the front panel, you can make full use of various functions easily.


  • High speed of DC to 200 kHz is realized.
  • Four-quadrant behavior is able to source and sink current.
  • It is possible to generate non-distortional waves such as sine waves and rectangular waves.
  • It is possible to set and operate the highly accurate program of 1024 steps.
  • Individual setting of DC and AC is possible. Superior usability is realized together with simplified operability.
  • 2 modes operation of CV (constant voltage) and CC (constant current) are applicable.
  • It is possible to connect a maximum of 3 power supplies in parallel (synchronized trigger) by coinciding accuracy of frequency (synchronized clock) in synchronized operation.
  • External digital control is available (Option).
  • It is possible to output voltage/current in 16 bits and customized original waveforms of resolution of 1024 in one cycle by using dedicated software.

Operation range

Output range


  • Voltage fluctuation tests for automotive electrical components such as car navigation system
  • Voltage fluctuation tests for automotive battery (Simulation of the waveform of cranking)
  • As Constant current power supply for electromagnet
  • Tests of various DC motors
  • The test which applies ripple current to a capacitor
  • Examination to evaluate the characteristic of the magnetic material
  • As high speed power supply for pulse plating
  • For measuring the loss of a transformer or a reactor
  • The test which applies transient current to a breaker or relay
  • To drive piezoelectric elements
  • Evaluation of Solar inverters (PV inverters)
  • Solar inverter testing

This product is not designed for charge and discharge of battery.
For battery charging and discharging applications, please refer to the Battery Cycle Tester product page.


We can manufacture other specified voltage, current and frequency band written as followings.

Model Maximum output Frequency Bandwidth (-3 dB)
Voltage Current Power CV mode CC mode
DOEF20-20 ±20 V ±20 A 400 W DC to 200 kHz DC to 100 kHz
DOEF40-10 ±40 V ±10 A 400 W
DOEF60-10 ±60 V ±10 A 600 W
DOEF60-20 ±60 V ±20 A 1200 W


Basic waveform generation

DOEF is equipped with a built-in function generator that produces basic waveforms such as sine, rectangular, and triangle waves.
Frequency range can be set between 0.01 Hz and 200 kHz. Easy adjustments/editions of amplitude, initial phase (for Sinewave), phase shift (for sine wave), and duty ratio (for rectangular/triangle wave) are possible. DOEF has special features of "soft start" and "soft stop," which enable initial program rise and fall characteristics of the output.

Starting phase Starting phase
Soft start Soft start

AC Volt/Current sweep, frequency sweep

Soft stop Soft stop

DC Volt/Current ramp


Power activation test, various start-up tests of motor, fluctuation test of the wave shape, etc.

Sequence functions

DOEF is equipped with sequence function that can program parameters such as step time, step amplitude ramp, DC voltage and current ramping, AC voltage and current ramping, frequency sweep, AC superposition, step jump, and jump times. These useful functions help to program the desired waves in very flexible manner, resulting to support efficient laboratory and research works.

Very complex sequence can be created easily with the easily understandable display.
Sequence programming function
Sequence programming function
  • Step setting time 0.1 ms to 1000 h (resolution of 0.1 ms)
  • Maximum 1024 steps per program.
  • Maximum 64 programs can be stored in memory for each CC/CV operation
  • Program repeat can be set by "endless repeat" or "1 time to 10000 times"
  • Multiple programs can be converted to activate
Image of Programs
Image of Programs

Sequence programming functions help to create complicated waves like the below to be simply and easily edited.

Pulse current variation Pulse current variation
Ripple current superpose Ripple current superpose
AC voltage variation AC voltage variation
DC voltage interruption DC voltage interruption

Measurement Function

DOEF is equipped with a measurement function that can measure DC value, AC RMS value, and Max/Min value, likewise, it is possible to automatically measure wide range bandwidth from DC to 120 kHz. There are 4 parameters that are simultaneously displayable, and each of these parameters is individually programmable. As this measurement is a standard feature, no option needs to be purchased. This sophisticated feature will reduce the time for editing output waves and bring up work efficiency.

Ex.) Measurement of AC waveform
Measurement Function 1
Ex.) Measurement of DC + AC waveform
Measurement Function 2

Synchronized operation (-Lso option)

The following DOEF operations are available for up to three units.

Synchronous trigger
Through a single operation of the master unit, it is possible to match the output timing of ON/OFF in one or two slave units. In turning the output on, the output starting gap between the master and the slave is less than 0.5 µs
* When this option is selected, we provide two meters of dedicated cables for the synchronized trigger function used for two or three devices.
Synchronous clock
By providing the clock input of 10 MHz, the individual difference between the oscillators installed on each unit is removed (In the case of this, there are a few ppm up to several tens ppm in general). What is more, frequency accuracy and sequence-step time are completely unified through the operation.
Moreover, the product is also available for setting the phase shift difference for the sine wave toward each unit.
(* Please prepare the coaxial cable on both ends of BNC connectors which is not included but required for synchronous clock
* When the slave unit is required to synchronize in accordance with the waveform set by the master unit, -LMs option must be taken (in master/slave control). Meanwhile, selecting -LSo option and -LMs option simultaneously is not allowed.
Other functions:
Protection function (shutdown or limit settable individually), Key lock function, Switching CV/CC, and Memory function (up to 99) are installed as standard.

Control Interface

Control Interface
  1. Display: Display various settings and measurements.
  2. OUTPUT switch: ON/OFF for output
  3. Rotary encoder: Change value
  4. POWER switch: ON/OFF for main power
  5. CANCEL switch: Cancel settings
  6. ENTER switch: To confirm and key in
  7. CV/CC switch: Switch over CV/CC mode
  8. DC/AC-DC switch: Switch DC/AC+DC mode
  9. SETTING/STORAGE switch: Make to setting change menu, store memory
  10. PROTECTION switch: To switch protection setting menu
  11. Shift down switch: Shift down each setting items
  12. Shift up switch: Shift up each setting items
  13. SEQUENCE switch:Use for switchover of sequence screen or interrupt or restart of sequence operation
  14. Shifting left/MEMORY switch: Shift digits of settings to left and also use switchover memory screens.
  15. Shifting right/LOCK switch: Shift digits of settings to right and also use key lock function


For details, download the datasheet below.



CC-Link interface board *
It enables digital remote control via a network of CC-Link. We may accept optimization for specific industrial networks such as Device NET. Please inquire our sales staff for details. Contact us


Optical interface board *
With optical communication, isolation control is performed. As complete isolation is performed by means of optical fiber, this enables advanced prevention of erroneous operations involved with transient phenomenon caused by surges, inductive lightning, external noise, etc.

  • -LGob:Optical interface board + optical cable 2 meters
  • -LGob(Fc5):Optical interface board + optical cable 5 meters
  • -LGob(Fc10):Optical interface board + optical cable 5 meters
  • -LGob(Fc20):Optical interface board + optical cable 5 meters
  • -LGob(Fc40):Optical interface board + optical cable 5 meters
Select the optional optical interface board (-LGob) when using the Bipolar power supply under the following conditions.
  • Noisy environment including factories (Example: Motors or coils are used near power supplies and loads).
  • Using with high voltage floating (more than 250 V).
  • Installation distance of 2 meters or more between the Bipolar power supply and a controller such as a computer, laptop, or Programmable Logic Controller (PLC).
[Control item]
Output ON/OFF, Voltage/Current setting (AC and DC), Switch of constant voltage/constant current, Frequency setting, Waveform setting (sine wave, square wave, and triangular wave), Phase setting (sine wave), Duty setting (square wave and triangular wave)
(The converters are required sold separately. Please contact our sales staff for details.)

*Adapter (CO/USB series) is required separately for control via digital interface.

-LMsm, -LMss

Master/Slave control (parallel operation)
Maximum 3 units including master unit are hooked. "-LMsm" for the master unit and "-LMss" for slave units. Please order the required number of units. Every master unit and slave unit is for exclusive use, but operating individually is also available. When changing the combination of master/slave, they should be readjusted in our shop.
In addition, either communication option (-LGob, -LCk, or -LUs1) is necessary for a master unit when the power supplies in the master-slave connection are controlled by digital communication. Slave units also require these options for their individual operation. (-LGob, -LCk or -LUs1) (It is impossible for this to select "-LSo" option simultaneously.)


Synchronized operation
Maximum 3 units can be operated in parallel.
Accuracy of output frequency and sequence time coincide by synchronizing with multi-units and it is possible to output the same wave altogether. Only in the case of a sine wave, it can output with phase difference given.
One dedicated cable (length: 2 meters) for the synchronized trigger is attached, except a cable used for synchronized clock function.
(It is impossible for this to select -LMsm, -LMss option simultaneously.)

-LUs1 *

USB interface board
Enable digital control with USB. One power supply can be connected per one USB port which the computer equipped.
In case the USB port which the computer equipped is not enough, please use a USB hub. However, depending on the USB hub, it may not work correctly.
OS: Microsoft Windows XP/Vista/7/8/10 (Both 32-bit version and 64-bit version are available.)

Microsoft Windows is a registered trademark of Microsoft Corporation in the United States and other countries


Shifting function for output voltage
Optional 120 Vp-p within the range of -115V to +115 V (only for DOEF60-10 and DOEF60-20).

* These options cannot be selected together. Only one of each can be selected.

How to Order

When ordering, add option No. to the Model No.
Example: DOEF40-10-LMsmUs1, DOEF60-10-LGob(Fc5)SoVs


Interface adapters (sold separately)

To use the optical interface, you need to prepare an optical interface adapter separately. The following interface adapters are available according to the communication method of your controller port.

Adapter for LAN
A total of 32 units can be connected to one CO-E32.
LAN cable is not provided.
Adapter for USB
A total of 32 units can be connected to one USB-OPT.
USB cable is not provided.
Adapter for RS-232C (9 pin)
A total of 32 units can be connected to each CO-OPT2-9.
Adapter for RS-232C (25 pin)
A total of 32 units can be connected to each CO-OPT2-25.
Adapter for RS-485 (25 pin)
A total of 32 units can be connected to each CO-OPT4-25.
Adapter for GPIB
A total of 32 units can be connected to one CO-G32.
GPIB cable is not provided.
-LGob: Optical Interface Board

(A) Optical fiber cable
As of models with -LGob option, a two-meter cable is provided in each unit. If you need a longer cable, please consult with our sales staff.

For details, refer to CO/USB series datasheet.

AC input cable

400 W model
CABLE TYPE8 CABLE series | AC input cable | Matsusada Precision CABLE series | AC input cable | Matsusada Precision 125 V / 125 A 2.5 meters

Fixed length

more than 600 W model
CABLE TYPE5 CABLE series | AC input cable | Matsusada Precision CABLE series | AC input cable | Matsusada Precision 300 V / 25 A 2.5 meters
Sold separately
400 W model
CABLE TYPE3 CABLE series | AC input cable | Matsusada Precision CABLE series | AC input cable | Matsusada Precision 250 V / 10 A 2.5 meters

Fixed length

Sold separately
400 W model
CABLE TYPE4 CABLE series | AC input cable | Matsusada Precision CABLE series | AC input cable | Matsusada Precision 250 V / 10 A 2.5 meters

Fixed length


For details, download the datasheet below.

Tech Notes

As for characteristics of amplifiers

Rise time

(step time) : responsiveness may be expressed with rise time. (see right figure)
Rise time for amplifiers in fc (Hz) of response time (=frequency band) is calculated with the following equation generally.
"tr ≈ 0.35/fc"
Decay time tf is equal to tr.
Frequency bandwidth
: at 30 kHz or lower, tr ≈ tf = around 12 μs
: at 20 kHz or lower, tr ≈ tf = around 18 μs

Rise time

Response speed

When an accurate output wave is required, please select an amplifier in a sufficiently higher frequency band than the applied one. Generally, speedy frequency bands as 3 times to 5 times of applied frequency for the sine wave and 10 times for rectangular waves are required. If the frequency band is in lacking, as not only output oscillation is reduced but also the phase difference of input and output become larger, consideration to apply it monitoring output wave is required.

Response speed

For Capacitive Loads

In the case of capacitive load, oscillation may be caused. If so, please insert a power resistance to the output in series.
And, in capacitive load, please attend that the frequency band is limited by the resistance and capacity inserted in series.

For Inductive Loads

At CC mode, oscillation may be caused by the inductance of inductive loads.
If so, please connect the C-R straight circuit between output terminals so as not to cause oscillation.

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