This current sensor is a carrier board or breakout board for Broadcom's ACHS-7121/7122/7123 Hall effect-based linear current sensors; we therefore recommend careful reading of the ACHS-7121/7122/7123 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 mO, 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 -40°C to 110°C.
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.
The ACHS-7122 sensor operates at 5 V and is designed for bidirectional input current from -20 A to 20 A. When Vcc is 5 V, the output voltage is centered at 2.5 V and changes by 100 mV per amp of input current, with positive current increasing the output voltage and negative current decreasing the output voltage.
This board ships assembled with all surface mount components, and a 3×1 strip of 0.1" header pins is included but not soldered in.
|Size:||0.7" x 0.8"|
|Current sense:||0.100 V/A1|
|Minimum logic voltage:||4.5 V|
|Maximum logic voltage:||5.5 V|
|Supply current:||15 mA|
|Version:||-20A to +20A|
1. When Vcc is 5 V.
1x Pololu ACHS-7122 Current Sensor Carrier -20A to +20A