This paper presents a true RMS-DC converter based on DDCC building block. Working over a wide range of input current (10 mu A-100 mu A), utilizing a general purpose building block and using a small value capacitor; makes this circuit a good candidate for biomedical and analog signal processing applications. Circuit is implemented using standard current-mode building block (DDCC). Compared with previous works, this circuit calculates True RMS of the arbitrary shaped input current over a wider range of amplitude with a higher accuracy where the output RMS value deviate the real value no more than 3% in selected input shapes.