Current probe for PCB tracks

TTi has launched a new type of current probe which is capable of measuring currents in PCB tracks directly.

Calibrated measurement of current normally requires either the insertion of a shunt resistor, or for the conductor to be passed through a closed magnetic loop. Typically this is done using some form of split clamp device. Whereas this is suitable for individual wires, it is of no use for measuring current in PCB tracks.

The I-prober 520 current probe uses a patented technology to observe and measure current without the need to break or surround the conductor. By placing the insulated tip of the probe onto a PCB track, the current flowing in the track can be observed and measured. The current trace is made visuable on an oscilloscope.

The probe has a bandwidth of DC to 5MHz and a dynamic range of 10mA to 20A pk-pk. You can use the probe with any oscilloscope having a 1 MOhm input.
The I-prober 520 uses a patented miniaturised version of a fluxgate magnetometer, to measure the current. It is the patented miniaturisation that enables it to measure the field at a precise point in space. In addition, the miniature sensor has much lower noise and much wider bandwidth than a conventional fluxgate magnetometer.

The I-prober 520 operates by sensing the field in very close proximity to the track. To achieve a calibrated measurement, the field sensor must be capable of maintaining a precise distance from the track. To achieve good sensitivity this distance must be very small because field reduces with the square of distance (to a first order approximation).

Beside PCB tracks, the probe can of course also be used on component leads or any other current carrying conductor. An interesting example is ground planes where it can be used to observe circulating currents, interference injection points and hot spots in order to optimise design.

The I-prober 520 is supplied with a control box and calibrator, power supply, and a clip on toroid assembly which can convert it into a closed loop current probe.

For detailed information about the I-prober click here.