Switched-capacitor pipelined logarithmic A/D and D/A convertors

The authors present two switched-capacitor circuits with modest complexity to implement a pipelined logarithmic digital-analogue convertor (LDAC) and logarithmic analogue-digital convertor (LADC), respectively, which spend only one clock time per conversion. In addition, the effect of the capacitor-ratio mismatch on the conversion errors of the convertor circuits is discussed. Hence, from the available maximum capacitor-ratio value and mismatch of the present integrated circuit (IC) technology, the feasible bit length of the pipelined LDAC and LADC can be computed