MLX91205
IMC-Hall
®
Current Sensor (Triaxis
®
Technology)
3901091205 Page 8 of 14 Data Sheet
Rev 012 June/13
12 Applications Information
12.1 Low current measurement up to ±2 A
Low currents can be measured with the MLX91205 by
increasing the magnetic field via a coil around the sensor.
The sensitivity (output voltage vs. current in coil) of the
measurement will depend on the size of coil and number
of turns. Additional sensitivity and increased immunity to
external fields can be gained by adding a shield around
the coil. The bobbin provides very high dielectric isolation
making this a suitable solution for high voltage power
supplies with relative low currents. The output should be
scaled to obtain the maximum voltage for the highest
current to be measured in order to obtain the best
accuracy and resolution.
12.2 Medium current up to ±30 A
With a single conductor located on the PCB, currents in
the range of up to 30 amps can be measured. The sizing
of the PCB trace needs to take into account the current
handling capability and the total power dissipation. The
PCB trace needs to be thick enough and wide enough to
handle the RMS current continuously.
The differential output voltage for this configuration can be
approximated by the following equation:
Vout = typ. 35 - 40 mV/A * I
For a current level of 30 A, the output will be approximately
1050 mV.
12.3 High current measurement up to ±600 A
Another method of measuring high currents on PCB’s is to
use a large thick gauge copper trace capable of carrying
the current on the opposite side of the PCB. The
MLX91205 should be located near the centre of the trace,
however because the trace is wide, the output is less
sensitive to location on the PCB. This configuration also
has less sensitivity due to the distance and width of the
conductor.
