Surge Specification
An international electromagnetic compatibility standard defines the immunity requirements and test methods for electronic equipment subjected to unidirectional surges caused by overvoltages from switching and lightning transients. Compliance with en 61000-4-5 ensures that circuit assemblies can withstand high-energy disturbances on power and interconnection lines. The standard specifies different test levels based on the intended operating environment of the equipment.
Protective components on the board must absorb or divert these transient pulses.
Generator Calibration
Standardised surge generators produce a specific combination wave with a defined open-circuit voltage rise time and short-circuit current rise time. During the calibration phase for en 61000-4-5, the test equipment must generate a 1.2 by 50 microsecond voltage waveform and an 8 by 20 microsecond current waveform. These precise timings ensure the test is repeatable across different test laboratories.
Measurement instrumentation verifies that the peak voltage and current levels remain within the tolerances specified by the standard before any device under test is connected to the generator.
Compliance Assessment
Post-test evaluation classifies the performance of the device under test into distinct levels of degradation or loss of function. Testing under en 61000-4-5 requires that the circuit board continues to operate or recovers automatically depending on the performance criteria. Damage to onboard voltage regulators or blocking diodes constitutes a failure.
