ADI’s ETU Solution for Low Voltage Circuit Breakers



An Electronic Trip Unit (ETU) is programmable device which measures and times current flowing through the low voltage circuit breaker (MCCB and ACB) and initiates a trip signal when appropriate. As modern low voltage power distribution system requires more communication/intelligent function to realize a higher level system features (e.g. zone Interlocking), a micro-processor based electronic controller unit is becoming more and more popular in the low voltage switchgear/breaker system. ADI offers a simple system solution.

ADI offers:
  • ADP2450 from Analog Devices is an ASSP specially designed for low voltage circuit breaker like MCCB and ACB
  • It includes a low power shunt boost controller to convert a current source (output from current transformer) into voltage source and a buck regulator which can effective regulate out a 3.3V/5V/Adj power supply
  • 4x programmable PGAs with 15 different gain setting option and one general purpose OPAMP have been integrated into the ADP2450
  • 4x threshold value programmable analog trip unit inside, that support both single coil and dual coil user case
  • Simplify ETU system design that only use ADP2450, low power MCU and interface


To Learn more about the comprehensive and flexible Analog Devices system solutions and main products,click here to get the complete solutions for free.

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System Block Diagram



Design Resources

3rd Party Reference Design

    TianJin Free Soar Innovations Technology Co., Ltd. —
    •  Measurement functions: currents, voltages, frequency, energy, frequency factor, etc.
    •  Protection functions
    •  MCCB ETU and support RCD function
    •  LCD display
    •  Support RS-485 and Modbus-RTU protocol


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