The SparkFun Current Sensor Breakout is a high accuracy board that utilizes the ACS723 for moderate AC and DC current sensing applications. The ACS723 sensor uses a Hall effect sensor to output a voltage relative to the current flowing through the IP+ and IP- pins on the board. The SparkFun Current Sensor Breakout measures both DC and AC currents all the way up to 5A, has full electrical isolation of measured and sensed circuits, and has a base sensitivity of 400mV/A. Although the analog output is adjustable to 80kHz, the bandwidth on the ACS723 Sensor Breakout width filter has been set to 20kHz to reduce noise when using at high gains.
The full 80KHz bandwidth that the sensor is capable of can be recovered by closing the JP1 (Bandwidth Select) jumper on the back of the board. The ACS723 sensor uses a Hall effect sensor to output a voltage relative to the current flowing through the IP+ and IP- pins. The advantage of using a Hall effect sensor is that the circuit being sensed and the circuit reading the sensor are electrically isolated. The amplified breakout board (Low Current) is capable of sensing very small currents down to around 10mA and large currents up to 5A! However, since the output is analog, your usable readings will be limited by noise and the resolution of the ADC reading the output. This sensor is not recommended for current sensing lower than 10's of milliamps.