Current Frequency Ratio (I/f)
This specification is the frequency equivalent
of the time-current product for pulse applications.
If the ratio of peak current to frequency exceeds
the rating, the core will saturate.
Low-Frequency 3 dB Point
This spec is the frequency equivalent to the droop.
For accurate measurements, the lowest frequency
to be viewed should be a decade higher than the
lower 3 dB point. DC current will move 3dB point
to a higher frequency (see section:
Effect of DC Current on Lower 3dB Frequency)
High-Frequency 3 dB Point
This spec is the frequency equivalent of the risetime. As a first approximation
a 10 ns risetime is equivalent to a 35 MHz high frequency 3 dB point. For accurate
measurements, the highest frequency to be viewed should be a decade lower than
the high-frequency 3 dB point. If higher frequencies have to be accurately known,
a model with a superior high frequency response and/or a curve displaying sensitivity
vs. frequency may be requested from the factory for the model in question.
Maximum RMS Current
Is determined by internal heating of the monitor.
The listed values are for frequency of 1 kHz or
less. Additional restrictions may apply for higher
frequencies. For high sensitivity models, the
50Ω feed-through termination at the scope
might be the principal limiting element. This
occurs when the square of the RMS value of the
output voltage [Vout= sensitivity x Primary Current]
divided by 50 ohms exceeds the power rating of
the feedthrough termination. To alleviate this
limitation, IPC offers for sale a 15W, 50Ω
feed-through termination.
Insertion Loss
Placing an IPC current monitor around a current-carrying conductor is equivalent
to inserting a small series resistance. This series resistance depends strongly
on the sensitivity of the monitor. For sensitivities of 1, 0.1, and 0.01 V/A,
the respective insertion resistances are 20, 0.6, and 0.06 milliohms.
