Flexible Digital Precision Amplifier

PEPPER: Flexible Digital Precision Amplifier

PEPPER is a development board containing a highly accurate digital amplifier.
Topview of the PEPPER boardPEPPER is ideal for the control, characterization and testing of power components such as power supplies, transformers, inductors, actuators and motors. A special feature of this amplifier is that it can control output of both voltage and current and that all kind of load impedances (from capacitive to inductive) can be connected. PEPPER is extremely flexible, accurate, efficient and broadband. The design of this amplifier can be integrated for unique applications in a customer-specific solution.

PEPPER is a 4-channel platform which is made up of state-of-the-art Gallium-Nitride (GaN) FETs. The output signals are well filtered so that interference signals, such as may occur with conventional motor drives, have no effect. EMC compliance will be considerably simpler and the filtering also reduces disturbances within the system itself.

PEPPER is implemented as an FMC (FPGA Mezzanine Card) card so that it can be connected to the MINT of 3T. Through the use of FMC it is compatible with most of the third-party FPGA or microcontroller development boards. In combination with the MINT, it is a very flexible amplifier in which the control algorithm can be implemented in the FPGA part or the ARM portion of the Arria V System-On-Chip.

To reduce the design effort and simplify verification, the control algorithm can be developed in MATLAB / Simulink. After correct simulation of the control algorithm, Model Based Design can be used to generate VHDL / C / C + code. Using Hardware-in-the-Loop (HIL), the control algorithm can then be validated on PEPPER with MATLAB / Simulink.


  • High Power Density which makes compact design possible
  • High efficiency, accuracy and bandwidth
  • Low noise and ripple
  • Pulse Width Modulation (PWM) or Pulse Density Modulation (PDM) control
  • Good EMC and EMI characteristics
  • Robust: Overload and short-circuit protection
  • Configurable as source or load
    • current, voltage, power, impedance
    • Wide impedance range: inductive, resistive (positive / negative), capacitive
    • Parallel and / or bridged switchable: higher current, four-quadrant, lower ripple

Technical specifications

Technology: GaN FETs (Si or SiC FETs possible)
Number of channels: 4
Supply Voltage: 0V to 50V
Output voltage: 0V to 48V
Output Current: – 5A to +5A
Output Ripple: < 50 mVpp at 50V
Current Noise: < 500 uArms at 5A
Efficiency: upto 98%
Output Power: 4 x 48V x 5A = 960W
Inputs: 2 x Hall/Encoder input
Form factor: FMC card compatible with most evaluation boards
  Compatible with the 3T MINT

Application examples

PEPPER can used in the role of both source and load and the output characteristics are fully adjustable. This makes it ideal for precision actuator control and characterization of, for example:

  • Voice coil or Lorentz actuators
  • Solenoids
  • Variable reluctances
  • Motors (DC, brushless, AC induction, sensorless, ironless, 2 or 3 phases)
  • Piezos
  • Laser and LED modulation
  • Heaters
  • Precision programmable power supply, voltage / current limited
  • Active loads
  • Battery cell charging, decharging, characterization (load curves, lifetime, automatic endurance tests)

Design services

3T has extensive knowledge and experience in the design and realization of customer specific hardware. We can also integrate PEPPER into your customer specific solution.