I am trying to sense the AC voltage and AC current using the sensors LV25 (Voltage sensor) and LA55 (Current sensor). Also I am using Arduino Duemilanove Atmel ATSAM3X8E-AU ADC whose pins are 3.3V compliant. So, my question is how to interface them with Arduino ADC pins and what external circuitry it needs ?
You face a double challenge, since the sensors (at least the LV25..) operates on a split supply, +/-12-15V. That means the sensor output can go negative. You also have to scale the output, which can be done with a voltage divider. Because of this complication, it is best if you post a schematic showing the power supply arrangement in your system.