This current sensor is a carrier board or breakout board for Broadcom?s ACHS-7121/7122/7123/7124/7125 Hall effect-based linear current sensors; we therefore recommend careful reading of the ACHS-7124/7125 datasheet (1MB pdf) before using this product. The following list details some of the sensor?s key features:

• The conductive path internal resistance is typically 0.7 m?, and the PCB is made with 2-oz copper, so very little power is lost in the board.
• Use of a Hall effect sensor means the IC is able to electrically isolate the current path from the sensor?s electronics (up to 3 kV RMS), which allows the sensor to be inserted anywhere along the current path and to be used in applications that require electrical isolation.
• 80 kHz bandwidth that can optionally be decreased by adding a capacitor across the board pins marked ?filter?.
• High accuracy and reliability: typical total output error of 1.5% at room temperature with factory calibration, an extremely stable output offset voltage, and almost zero magnetic hysteresis.
• Robust sensor IC can tolerate 100 ms transient current spikes up to 100 A.
• Wide operating temperature range of -40C to 110C.

The pads are labeled on the bottom silkscreen, as shown in the picture to the right. The silkscreen also shows the direction that is interpreted as positive current flow via the +i arrow.

We sell five different versions of this board (10A, 20A, 30A, 40A, and 50A) so you should consider adding your own distinguishing marks or labels if you will be working simultaneously with multiple versions. A white box is provided on the bottom silkscreen of the board to make labeling easier. You can also distinguish the versions by reading the text on the IC.