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Current Probes

The Voss Scientific CP-450 High Bandwidth Current Probe responds to CW or transient current signals on a wire. Its flat frequency response (500 kHz to beyond 4.5 GHz), and a 75 psec step response, make the CP-450 ideal for current measurements in such areas as high-power microwave coupling experiments, EMC/EMI testing of complex systems, electrostatic discharge testing, and any experiment involving electrical signals with temporal phenomena to time scales below 100 ps.

CP - 450 Current Probe

For direct-injection testing, the probe can be used to impress waveforms onto signal lines. When an insulated wire (up to 1.5 mm in diameter) is passed through the opening of the probe's compact housing and carries a current, the CP-450 High Bandwidth Current Probe will produce an output signal related to the current on the wire as

Vsensor = Zt Iwire,

which is taken from the attached SMA connector. The CP-450’s typical frequency domain response is shown in the figure, which also shows that the nominal transfer function value = -29 dB ( 2 * transfer impedance).

Experimentally verified features of the CP-450 include:

  • A 50 Ω, SMA-type output port housed in a sturdy stainless-steel enclosure, with overall dimensions of 3 cm long * 1 cm wide * 0.7 cm thick;
  • A nominally flat frequency response (+/- 1.5 dB) to 4.5 GHz, with a stable phase response to well above rated frequencies, and a step response of < 75 ps;
  • An insulation capability of 1500 V peak for transient signals (1 ns duration maximum), less for CW signals (signal strength and duty cycle dependent);
  • A saturation limit of 20 amps and a volt-second rating of 1*10-6 ;
  • A 2 Ω typical transfer impedance with < 1 Ω injection impedance; and
  • Excellent rejection of capacitive electric field coupling.
    Voss Scientific verifies the frequency response and transfer impedance of each CP-450 High Bandwidth Current Probe to be within the specified limits before shipment. These verifications are carried out using the S-450 calibration fixture, which is also available to the end user to validate post-delivery performance of the sensor, and to determine the complete vector characterization of the sensor’s transfer function.
Voss Scientific 418 Washington St. SE Albuquerque, NM 87108
Phone: 505-255-4201 Fax: 505-255-4294