CURRENT TRANSFORMER 30A / 5A Interfacing with AVR Atmega32 ADC
Most current transformer use a resister in parallel to convert the current into voltage. This is because most ADC's are Voltage ADC's. The resistor should be chosen such that the peak expected current produces the maximum voltage that your ADC can read. There is one caveat. Your transformer says that it can/should only dissipate 2.5VA (watts) into the load.

Calculation for the resistor is: V_adc_max/I_current_transformer_max = Resistance. Also 2.5 >= (I_current_transformer_max)^2 * Resistance.